Methods And Kits For Theranostic Applications

ABSTRACT

The present disclosure is directed to methods and kits for identifying, enriching, and evaluating templated assembly reactants. Some embodiments disclose methods for identifying templated assembly targets by synthesizing templated assembly reactants, hybridizing the templated assembly reactants to target nucleic acids, performing a templated assembly reaction, and identifying the target nucleic acids that hybridized to the templated assembly reactants. Libraries of templated assembly reactants, a kit for identifying templated assembly targets, and a pair of templated assembly targets enriched from a library of chemically-ligated oligonucleotides spatially elicited (CLOSE) products are also disclosed.

FIELD

The present disclosure provides for the identification, enrichment, andevaluation of templated assembly targets.

BACKGROUND

A goal of drug development is delivering potent bio-therapeuticinterventions that are specific for pathogenic cells, such as virusinfected cells, neoplastic cells, cells producing an autoimmuneresponse, and other dysregulated or dysfunctional cells without risk oftoxicity to adjacent normal cells or the overall health of the patient.Unfortunately, developing these agents is extremely difficult.

A method that has emerged to allow delivery of potent interventions topathogenic cells while mitigating toxicity to normal cells is targetingtherapeutics against molecular markers specific for pathogenic cells.Targeted therapeutics have shown extraordinary clinical results inrestricted cases, but are currently limited in their applicability dueto a lack of accessible markers for targeted therapy. It is extremelydifficult, and often impossible, to discover protein markers for manypathogenic cell types.

Existing nucleic acid-targeted therapies, such as siRNA, are able todown-modulate expression of potentially dangerous genes, but do notdeliver potent cytotoxic or cytostatic interventions and thus are notparticularly efficient at eliminating the dangerous cells themselves.

Hence, there exists a need to develop highly targeted therapeuticswithout the poor efficacy and/or severe side effects of existinginterventions.

SUMMARY

The present disclosure is directed to methods and kits for identifying,enriching, and evaluating templated assembly targets.

Some embodiments are directed to methods for identifying templatedassembly targets including synthesizing a first population of templatedassembly reactants and a second population of corresponding templatedassembly reactants, wherein the first and second populations oftemplated assembly reactants comprise oligonucleotide sequences;hybridizing both populations of templated assembly reactants to targetnucleic acids; performing a templated assembly reaction, wherein thehybridized first population of templated assembly reactants and thehybridized second population of corresponding templated assemblyreactants undergo templated assembly; and identifying the target nucleicacids that hybridized to either the first or second population oftemplated assembly reactants that underwent templated assembly, whereinthe hybridized target nucleic acids are the templated assembly targets.

In some embodiments, synthesizing the first and second population oftemplated assembly reactants can include synthesizing random orgene-specific oligonucleotides sequences of about 5 to about 100nucleotides long or about 7 to about 30 nucleotides long. The templatedassembly reactants can also include nuclease-resistant phosphodiesterbackbones or nuclease-resistant sugar moieties. The templated assemblyreactants can include a 5′ or a 3′priming site adjacent to theoligonucleotide sequences. The populations of templated assemblyreactants can also include modifications, such as a 5′-azide and a3′-alkyne group; a 5′-alkyne and a 3′-azide group; and anN-hydroxysuccinimide and a cyclooctyne on corresponding populations. Themodification can be specific for a traceless Staudinger ligationselected from either a traceless phosphinophenol Staudinger ligation ora traceless phosphinomethanethiol Staudinger ligation. The templatedassembly reactants can also include a spacer or linker, such as at least6 carbon atoms.

In some embodiments, the method can include obtaining the target nucleicacids prior to hybridizing the populations of templated assemblyreactants to the target nucleic acids. Isolating nucleic acids from atarget sample can also be included in the methods.

In some embodiments, the target sample can be at least one of a cellpopulation, a tumor, a tissue, or an organ. The target nucleic acids canalso maintain their native secondary structures. The target nucleicacids can also include cellular nucleic acid templates, such as genomicor expressed genes for known oncogenes or tumor suppressors, cell cycleregulators and mediators, transcriptonal regulators and mediators,translational regulators and mediators, telomerases, cytoskeletalcomponents, and kinases.

In some embodiments, hybridizing both populations of templated assemblyreactants to the target nucleic acids can include removing unboundtemplated assembly reactants. Removing unbound templated assemblyreactants can also include removing the unbound reactants by at leastone of an enzymatic digestion, an ultrafiltration, or a gelsize-exclusion chromatography, or any combination thereof.

In some embodiments, the templated assembly reaction can be at least oneof a click chemical reaction, a Staudinger reduction, a non-tracelessStaudinger ligation, a traceless Staudinger ligation, a tracelessphosphinophenol Staudinger ligation, a traceless phosphinomethanethiolStaudinger ligation, a native chemical ligation, and a bio-orthogonalchemical reaction, or any combination thereof.

In some embodiments, identifying the target nucleic acids can includeremoving the hybridized first population of templated assembly reactantsand the hybridized second population of corresponding templated assemblyreactants that failed to undergo templated assembly.Microcompartmentalizing the reacted templated assembly reactants fromthe unreacted templated assembly reactants and/or amplifying thehybridized target nucleic acids, may also be included in theidentification. Additionally, sequencing the hybridized target nucleicacids can be used to identify the target nucleic acids.

The present disclosure is also directed to libraries of templatedassembly reactants for identifying templated assembly targets includingat least a first and second population of templated assembly reactants,where the templated assembly reactants include an oligonucleotidesequence and a modification for reaction in a templated assemblyreaction. Kits for identifying templated assembly targets including alibrary of oligonucleotides for identifying templated assembly targetshaving oligonucleotide sequences modified as corresponding templatedassembly reactants and reagents are also disclosed. Additionally, a pairof templated assembly targets enriched from a library ofchemically-ligated oligonucleotides spatially elicited (CLOSE) productshaving oligonucleotides chemically ligated due to their spatialproximity through hybridization to cellular nucleic acid templates isincluded.

The present disclosure is also directed to methods for enrichment of apair of templated assembly targets from a library of chemically-ligatedoligonucleotides spatially elicited (CLOSE) products including obtaininga library of oligonucleotides chemically ligated through templatedassembly due to spatial proximity to cellular nucleic acid targets,amplifying the library of ligated oligonucleotide-cellular nucleic acidtargets and selectively enriching for ligated oligonucleotide-cellularnucleic acid targets, wherein the ligated targets are selected forrelevance to a pathology of an aberrant cell of interest or to adiscontinuous hybridization to the cellular nucleic acid targets aredisclosed. The methods can also include removing ligated targets derivedfrom matched normal cells of interest.

Pairs of templated assembly targets enriched from a library ofchemically-ligated oligonucleotides spatially elicited (CLOSE) productscomprising oligonucleotides chemically ligated due to their spatialproximity through hybridization to cellular nucleic acid templates isalso included. The CLOSE library can be made of short PCR productduplexes of the chemically ligated oligonucleotides, such as fromamplified library of chemically ligated products or an amplified libraryof rearranged chemically ligated products. The oligonucleotides can bedifferentially enriched in a CLOSE library derived from aberrant targetcells as compared to a CLOSE library derived from normal cells. Theoligonucleotides can also be selectively enriched for ligated targetsdifferentially derived from aberrant target cells and not matched normalcells of interest.

The present disclosure is also directed to methods of evaluating a pairof chemically-ligated oligonucleotides spatially elicited (CLOSE)products for templated assembly including modifying the pair of CLOSEproducts as templated assembly reactants, transfecting the pair ofmodified CLOSE products into a target aberrant cell of interest, andscreening for templated assembly of the pair of modified CLOSE products.The CLOSE products can also be modified by adding a pyrene group, suchas pyrene maleimide, and/or including a spacer arm between the pyreneand maleimide.

BRIEF DESCRIPTION OF DRAWINGS

The appended drawings have been included herein so that theabove-recited features, advantages and objects of the disclosure willbecome clear and can be understood in detail. These drawings form a partof the specification. It is to be noted, however, that the appendeddrawings illustrate some embodiments of the disclosure and should not beconsidered to limit the scope of the claims.

FIGS. 1A, 1B, 1C, and 1D illustrate schematic configurations of: 1A)random decamer oligonucleotide (RDO); P1: Primer site 1; N10: randomdecamer tracts; Me-C: 5-methyl deoxycytidine residue; Ak: 3′-terminalalkyne, in the form of a 3′-propargyl group; 1B) RDO2; P2: Primer site2; N10: random decamer tracts; Az: 5′-terminal azide group; 1C) RDO1hybridized to a 2′-O-methyl oligonucleotide complementary to the primersite (RDO1:P1C); P1: Primer site 1; N10: random decamer tracts; Ak:3′-terminal alkyne, in the form of a 3′-propargyl group; and 1D) RDO2hybridized to a 2′-O-methyl oligonucleotide complementary to the primersite (RDO2:P2C); P2: Primer site 1; N10: random decamer tracts; Az:5′-terminal azide group; RDO1 and RDO2 are, for convenience, referred toas “Left” (L) and “Right” (R) oligonucleotides in the context of CLOSElibraries.

FIG. 2 shows representative hybridization-mediated spatial alignments oflabeled 5′- and 3′-ends of specific oligonucleotides from RDOpopulations, on either linear (contiguous) sites of discontinuous(conformationally-determined) sites; S1 and S2 denote selectedsubpopulations of decamers from the original random decamer totalpopulations.

FIGS. 3A, 3B, and 3C are representative diagrams showing productive andnon-productive hybridizations between specific oligonucleotides fromseparately 5′- and 3′-labeled random decamer populations; 3A)productive, from both 5′-azide and 3′-alkyne modified populations; 3B)non-productive, from 5′-azide modified populations only; and 3C)non-productive, from 3-alkyne-modified population only.

FIG. 4 shows representative examples of CLOSE clones (C1-C19) incomparison to an equal number of random oligonucleotides of the samepattern (Rnd1-Rnd17); CL1=TGGATCTCTGC (SEQ ID NO:1), TTAAAGTGACC (SEQ IDNO:2); CL2=TGAGTGTGTGC (SEQ ID NO:3), TGCGCACACTC (SEQ ID NO:4);CL3=ACGGGCCCGGC (SEQ ID NO:5), TTCGCGTCCAG (SEQ ID NO:6);CL4=TCTTTTACGCC (SEQ ID NO:7), TCTGCCCAGGC (SEQ ID NO:8);CL5=ACACCCTCGCC (SEQ ID NO:9), TACCTTCTCCC (SEQ ID NO:10);CL6=TCACATTCACC (SEQ ID NO:11), TTGTGGATGTG (SEQ ID NO:12);CL8=GGCCCTTCTAC (SEQ ID NO:13), TCGTCTGCGGC (SEQ ID NO:14),CL9=TTCAATGGGCC (SEQ ID NO:15), TTACCCAGTGC (SEQ ID NO:16);CL10=ATCAACCCTGC (SEQ ID NO:17), TGTATTCGCCA (SEQ ID NO:18);CL11=ACGCCGATTGC (SEQ ID NO:19), TGGCAGTCGGC (SEQ ID NO:20);CL12=ACCTAACAGCC (SEQ ID NO:21), TTCATCCGTTC (SEQ ID NO:22);CL13=TTGAACGATCC (SEQ ID NO:23), TAGGTCGTTCA (SEQ ID NO:24);CL14=ATAGAAGGGGC (SEQ ID NO:25), TTAGGCCAACA (SEQ ID NO:26);CL15=CCAACTGTAGC (SEQ ID NO:27), TAGGCGGTTGG (SEQ ID NO:28);CL16=CCCGGCCTCCC (SEQ ID NO:29), TTCCTAGCTGC (SEQ ID NO:30);CL17=AAACCGACAGC (SEQ ID NO:31), TATGCTGTCGG (SEQ ID NO:32);CL19=ATTCGCCCCCC (SEQ ID NO:33), TCCGCTTCGGT (SEQ ID NO:34);Rnd1=ACATAAGCAAC (SEQ ID NO:92), TTATCGTAGTC (SEQ ID NO:93);Rnd2=CGTCAAATTCC (SEQ ID NO:94), TAGCCCTGTTA (SEQ ID NO:95);Rnd3=TATGTGTCAAC (SEQ ID NO:96), TATGGCGTAG a (SEQ ID NO:97);Rnd4=ACTGGATTGAC (SEQ ID NO:98), TCTGTTTGACG (SEQ ID NO:99);Rnd5=GTACCTGCTGC (SEQ ID NO:100), TATCGGTACGG (SEQ ID NO:101);Rnd6=TGACCGAGAAC (SEQ ID NO:102), TTCTGTCGGGC (SEQ ID NO:103);Rnd7=ATACTTTCCAC (SEQ ID NO:104), TAACGCCCCGT (SEQ ID NO:105);Rnd8=ATCGATGCTGC (SEQ ID NO:106), TAACGAATCGA (SEQ ID NO:107);Rnd9=TGCACGCTCCC (SEQ ID NO:108, TCGTCTTTGAA (SEQ ID NO:109);Rnd10=AACGCATAAAC (SEQ ID NO:110), TCATACAAGTG (SEQ ID NO:111);Rnd11=GACAGATGATC (SEQ ID NO:112), TGGGTACGGGC (SEQ ID NO:113);Rnd12=CTCTAATACAC (SEQ ID NO:114), TTCCAACACTC (SEQ ID NO:115);Rnd13=TACGCCCTCTC (SEQ ID NO:116), TTCAAGAGCT a (SEQ ID NO:117);Rnd14=GAAGGGCACCC (SEQ ID NO:118), TCTGCAGTTGG (SEQ ID NO:119);Rnd15=AAAGGGAATTC (SEQ ID NO:120), TATTTCGTAAG (SEQ ID NO:121);Rnd16=GCGAGCCCATC (SEQ ID NO:122), TACCGTCATTC (SEQ ID NO:123);Rnd17=ATGCGGAAGAC (SEQ ID NO:124), TGTTAACACGA (SEQ ID NO:125).

FIG. 5 shows representative subtraction of CLOSE libraries from aberrantcell sources with CLOSE libraries from corresponding normal cells; P1-P4denote distinct priming sites; S1 and S2 denote selected decamer tractsfrom aberrant cells, from initially random regions; S3 and S4 denoteselected decamer tracts from corresponding normal cells, from initiallyrandom regions.

FIG. 6 shows a representative procedure for obtaining purifieddesthiobiotinylated ‘top’ strands (corresponding to strands of a primaryCLOSE library) by selection on solid-phase streptavidin, and elutionwith excess free biotin.

FIG. 7 shows representative selection of CLOSE clones on correspondingnormal cell RNA sources, to enrich for CLOSE clones absent from thenormal cellular background; desthiobiotnylated top strands are preparedas described herein.

FIGS. 8A and 8B are representative illustrations of pyrene labeling ofcandidate specific CLOSE decamers (A1 and A2) andexcitation-fluorescence generation; 7A) chemical conjugation of pyrenemaleimide to 3′- or 5′-terminal-SH groups; and 7B) excimer fluorescencefrom hybridization-induced spatial proximity.

FIG. 9 illustrates representative QPCR for quantitation of relativelevels of specific CLOSE clones as correlating with source RNA templatelevels; top: primary CLOSE clone chemically ligated population selectedby hybridization proximity, depicting the Cu(I) catalyzed triazolelinkage and two specific decamer regions A1 and A2; middle: the specificA1/A2 clone showing a second-cycle extension from the complement to P2,and an annealed QPCR probe with a 5′-fluor and 3′ quencher; bottom:completion of the extension (as in the middle diagram), with stranddisplacement and digestion of the probe to unquench the fluor and allowfluorescence quantitation.

FIG. 10 depicts representative digital PCR for a single candidate CLOSEpair, with specific decamer regions A1 and A2; after hybridization withtarget RNA and Cu(I) catalyzed chemical ligation, the number ofchemically ligated dimers approximates the number of template moleculesin the target RNA; the ligated products are prepared for digital PCR bycompartmentalization with molar excesses of primers and probes, andPCR-related buffer and enzyme requirements (Taq 1 DNA polymerase; otherschematic symbols, and the process for fluorescence generation), uponamplification, compartments bearing ligated dimers and matching primersand probe with the target dimer generate a fluorescent signal;enumeration of (+) signal compartments thus equates with the originalnumber of dimers present, and in turn approximates to the number oftemplate molecules.

FIG. 11 depicts a representative gel evaluation of +/−DNase-treatedCLOSE/RNA hybridization; lane 1, CLOSE oligonucleotides+RNAtemplate+DNase; lane 2, CLOSE oligonucleotides+RNA template withoutDNase; lane 3, CLOSE oligonucleotides with no template+DNase; lane 4,CLOSE oligonucleotides with no template and without DNase); resultsshowed presence of carry-over of CLOSE oligonucleotides irrespective ofthe presence of template (lanes 2 and 4), but only in the presence ofRNA template was a band observed post-DNase treatment (lane 1 vs. lane3); the band in lane 1 (amplified CLOSE oligonucleotides+RNAtemplate+DNase) corresponding the expected size for a chemically ligatedCLOSE dimer was excised and re-amplified with the original primers toincrease the available yield.

FIG. 12 depicts a representative gel analysis (2% agarose) of PEG testfor RNA/unhybridized CLOSE oligonucleotide separations; lanes 1-3: MU89RNA plus CLOSE oligonucleotides annealed with 2′-O-methyl protectorstrands; lanes 4-6; MU89 RNA plus CLOSE oligonucleotides withoutprotector strands; lanes land 4: final PEG pellets (2× precipitations);lanes 2 and 5: first PEG supernatants; and lanes 3 and 6: second PEGsupernatants.

FIG. 13 depicts in a representative schematic form a CLOSE process witha single PEG precipitation and DNase step.

FIG. 14 depicts representative CLOSE site nomenclature conventions; L-and R-CLOSE oligonucleotides hybridizing to discontinuous sites on atemplate can either have their chemically modified ends linearlydirected towards each other (“endo” configuration) or opposed to eachother (“exo” configuration); some configurations may accelerate effectorpartial reactivity, depending on: 1) distance between L and R sites (Nsequences as above), 2) flexibility of N and flanking sequences; and 3)secondary structures promoting spatial proximity.

FIG. 15 depicts representative discontinuous “endo” vs. “exo” siteswithin secondary structural loops; if hybridization sites are within aloop, the ends of an exo configuration can be spatially broughttogether, while the conventional endo orientation is poorly active.

FIG. 16 depicts representative non-contiguous structures: testing “endo”vs. “exo” configurations; no significant click reactions were observedin the absence of template, under the conditions used.

FIG. 17 depicts representative dependence of “exo” click on loopformation; the “control” sequences here have the G-C tracts whichpromote loop formation replaced with non-self-complementary sequences,such that no loops can form; no significant click reactions wereobserved in the absence of template, under the conditions used.

FIG. 18 depicts representative structures of stem loop templates used inFIG. 19.

FIG. 19 shows a representative demonstration of click reaction followinghybridization to discontinuous sites on a template strand; schematicdepictions of stem-loop oligonucleotides shown in FIG. 18; bands showpositions of click-ligated products (20-mers), distinguishable from thetemplate strands (30-mers).

FIG. 20 shows representative pyrene-labeled oligonucleotides PyeTO.1 andPye TO.2 annealed on wild-type and mutant HPV templates; for thewild-type sequence (HPV-1) the oligonucleotides are displaced from eachother by one base (boxed dA residue), unlike the HPV-0 template wherethey are immediately juxtaposed; for the HPV-2 and HPV-3 templates, thedisplacement is two and three dA residues respectively (boxed);TAACTGTCAAAAGCCA CTGTGTCCTGAAGAAAGCAAAGACATCTGGACAAAAAGC (SEQ ID NO:89);TAACTG TCAAAAGCCACTGTGTCCTGAAGAAAAGCAAAGACATCTGGACAAAAAGC (SEQ IDNO:35); TAACTGTCAAAAGCCACTGTGTCCTGAAGAAAAAGCAAAGACATCTGGACA AAAAGC (SEQID NO:90); TAACTGTCAAAAGCCACTGTGTCCTGAAGAAAAAAGCAA AGACATCTGGACAAAAAGC(SEQ ID NO:91); UCCAGAUGUCUUUGC-pyrene (SEQ ID NO:36),pyrene-UUUCUUCAGGACACAG (SEQ ID NO:88).

FIG. 21 shows induction of pyrene excimer fluorescence on specifictemplates in equimolar amounts; HPV-0, HPV-1, HPV-2, HPV-3;HPV-Scr=randomly scrambled template from HPV-0 sequences; NT=notemplate.

FIG. 22 depicts representative CLOSE Intersection software principle asa flow-chart, showing the processing pathway for each CLOSE clonesequence.

FIG. 23 depicts representative CLOSE intersection software principle.

FIG. 24 depicts representative CLOSE intersection software principle:example of a hit; the PLXNA3 sequence was found from CLOSE intersectionsoftware with a specific CLOSE clone, where the CLOSE matches were inthe EXO configuration (in such cases, the L-CLOSE match is closer to the5′ end of the target RNA sequence than the R-CLOSE match); the CLOSEsequences were replaced with the standard complements to the 10-merclick oligonucleotides used in these tests, in either EXO or ENDOconfigurations; no significant click reactions were observed in theabsence of template, under the conditions used; TGCGCTTCTGGGTGAATGTGATCAAGAACCCGCAGTTCGTGTTCGACATCCACAAGAACAGCATCACGG (SEQ ID NO:126).

FIG. 25 depicts a representative schematic of template titration effectwhen target template is in molar excess of effector partials.

FIG. 26 depicts a representative demonstration of template titrationeffect with pyrene fluorescence;TAACTGTCAAAAGCCACTGTGTCCTGAAGAAAAGCAAAGACATCTG GACAAAAAGC (SEQ IDNO:35); UCCAGAUGUCUUUGC-pyrene (SEQ ID NO:36), pyrene-UUUCUUCAGGACACAG(SEQ ID NO:88).

FIG. 27 depicts a representative demonstration of template titrationeffect with an RNA template in vitro; the assigned molar ratio of MU89RNA:click oligonucleotides is based on assuming average RNA size ofabout 1500 bases; GAAAUAGAUGGUCCAGCUGGACAA GCAGAA (SEQ ID NO:37);CTTGTCCAGCTGGACCATCT (SEQ ID NO:38).

FIG. 28 depicts representative target-directed CLOSE; a schematicexample of an expressed translocation, where two normal transcripts areeffectively fused together; while there is only one possible junctionsequence that can be targeted as a linear contiguous sequence, there aremany potential CLOSE sites formed through spatial proximity mediated byhigher-order RNA folding and secondary structures.

FIG. 29 depicts representative asymmetric PCR combined with biotinylatedbottom-strand removal.

FIG. 30 depicts representative target-directed CLOSE principle; theprobe “pulls out” CLOSE members with hybridizing sequences; these may,but not necessarily, include contiguous Left & Right CLOSE segments;discontinuous sites may thus be found by means of the linearhybridization probe.

FIG. 31 depicts a representative BCR-ABL segment used as a probe fortarget-directed CLOSE (1338 bases; SEQ ID NO:39); black text: BCRsequence; gray text: ABL sequence (junction at GAGTTCAA/AAGCCCTT; SEQ IDNO:44); priming sites for the relevant amplification primers areunderlined.

FIGS. 32A and 32B depict, respectively, a representative gelpurification method for target-directed CLOSE, and examples of clonesobtained with BCR-ABL probe, and examples of candidates for BCR-ABL (geldiagram: lane A: Boxed zone, long single-stranded probe afterhybridization with single-stranded CLOSE dimers ligated on target cellwhole RNA, thus bearing duplexed CLOSE clones with hybridizingsequences; lower molecular band, free excess CLOSE sequences; lane B:control lacking the long probe molecule; boxed zone, control region ofgel of the same mobility as for the probe sequence; lower molecularband, free excess CLOSE sequences); and two examples of cloned CLOSEclones from K562 RNA obtained from 2 cycles of BCR-ABL selection; foreach, the first sequence show the actual CLOSE 22-mers with theintervening CT dimers in gray (for dBBc2-01=ATAAGCACCTCTTCAAGGTCTG; SEQID NO:40; for dBBc2-08=TGACCTGCTCCTCACCCCTCCT; SEQ ID NO:41); thereverse complement (for dBBc2-01=CAGACCTTGAAGAGGTGCTTAT; SEQ ID NO:42;for dBBc2-08=AGGAGGGGTGAGGAGCAGGTCA; SEQ ID NO:43) to these strandscorresponds to the (+) strand for the BCR-ABL probe, or the whole RNAtranscript; underlined bold text shows BCR/ABL matches, with thecoordinates below (from a compiled 8703-base BCR-ABL full-lengthtranscript; the probe range spanned coordinates 2766-4103); the N valuecorresponds to the distance between the closest ends of the L- andR-matches.

FIGS. 33A and 33B depict representative schematic configurations of RDOswith terminal azide and cyclooctyne groups; P1, P2: primer sites 1 and 2respectively; N10: random decamer tracts; COT: 3′-terminal modifiedcycloalkyne; Az: 5′-terminal azide group.

FIGS. 34A and 34B depict, respectively, representative “unnatural” 5′-5′(head-to-head, A) and 3′-3′ (tail-to-tail, B) chemical ligation, drivenby hybridization-mediated spatial proximity resulting from secondarystructures of the target RNA strands; AZ, 5′ azide; COT, 5′ cyclooctyne.

FIG. 35 depicts representative single-stranded oligoucleotides with 5′click groups (azide, AZ and cycloalkyne, COT), initial random regions(N1 and N2), PCR primer sites (P1 and P2), and restriction site/primerregions (A1 and A2); S1 and S2 denote selected subpopulations ofdecamers from the original random decamer total populations; also shownis a head-to-head chemically-ligated click product resulting through RNAsecondary structural spatially proximal hybridization.

FIGS. 36A and 36B depict possible 5′ structures for 5′-5′ clickreactivity; 36A, 5′ hexynyl modification to supply an alkyne group; 36B,5′-azide group, provided through reaction of a 5′-amino group (with a6-carbon spacer from the 5′-hydroxyl) with N-hydroxylsuccinimide linkedby a 3-carbon spacer to an azide moiety, with subsequent formation on anamide linkage.

FIG. 37 shows representative production of double-stranded 5′-5′chemical ligation products by polymerase extensions, and subsequentrecutting with restriction endonuclease Age I (S1 and S2 denote selectedsubpopulations of decamers from the original random decamer totalpopulations).

FIG. 38 illustrates representative extensions incorporating5′-methyl-dCTP and using complementary segment to region A1;hemimethylated regions of resulting extended duplexes are indicated bygray background shading; S1 and S2 denote selected subpopulations ofdecamers from the original random decamer total populations.

FIG. 39 is a representative diagram showing partitioning of 5′-5′chemically ligated duplex products into in vitro microcompartments; hereeach fragment has been initially cleaved with restriction enzyme E2 (AgeI in the specified embodiment).

FIG. 40 depicts representative partitioning of unligated 5′-labeledduplex strands into microcompartments; here the 5′-cycloalkyne modifiedstrand has been previously cleaved in the A2 region with restrictionenzyme E2 (Age I in the specified embodiment).

FIG. 41 shows representative Xma I cutting (in the specified embodiment)and re-ligation of 5′-5′ linkages within microcompartments.

FIG. 42 is a representative illustration of cycling of Xma I cleaved5′-5′ ligation products (in the specified embodiment) inmicrocompartments, until irreversible and amplifiable rearrangementend-point is reached.

FIG. 43 is a representative diagram of single-stranded oligonucleotideswith 3′ click groups (azide and alkyne), initial random regions (N1 andN2), PCR primer sites (P1 and P2), and restriction site/primer regions(A1 and A2); S1 and S2 denote selected subpopulations of decamers fromthe original random decamer total populations; also shown is atail-to-tail chemically-ligated click product resulting through RNAsecondary structural spatially proximal hybridization.

FIGS. 44A and 44B depict representative possible 3′ structures for 3′-3′click reactivity; 44A) 3′ modification to supply a cycloalkyne group;44B) 3′-azide group, provided through reaction of a 3′-amino group (witha 6-carbon spacer from the 3′-hydroxyl) with N-hydroxylsuccinimidelinked by a 3-carbon spacer to an azide moiety, with subsequentformation on an amide linkage.

FIG. 45 illustrates representative production of double-stranded 3′-3′chemical ligation products by polymerase extensions, and subsequentrecutting with restriction endonuclease Age I; S1 and S2 denote selectedsubpopulations of decamers from the original random decamer totalpopulations.

FIG. 46 shows representative extensions incorporating 5′-methyl-dCTP andusing complementary segment to region A2; hemimethylated regions ofresulting extended duplexes are indicated by gray background shading; S1and S2 denote selected subpopulations of decamers from the originalrandom decamer total populations.

FIG. 47 is a representative illustration of partitioning of 3′-3′chemically ligated duplex products into in vitro microcompartments; hereeach fragment has been initially cleaved with restriction enzyme E2 (AgeI in the specified embodiment).

FIG. 48 diagrams representative partitioning of unligated3′-click-labeled duplex strands into microcompartments; here the3′-alkyne modified strand has been previously cleaved in the A2 regionwith restriction enzyme E2 (Age I in the specified embodiment).

FIG. 49 is a representative diagram of Xma I cutting (in the specifiedembodiment) and re-ligation of 3′-3′ linkages within microcompartments.

FIG. 50 shows representative cycling of Xma I cleaved (in the specifiedembodiment) 3′-3′ ligation products in microcompartments, untilirreversible and amplifiable rearrangement end-point is reached.

FIG. 51 illustrates representative single-stranded oligonucleotides withnon-polymerase readable 5′- and 3′-click groups (cycloalkyne and aziderespectively), initial random regions (N1 and N2), PCR primer sites (P1and P2), and restriction site/primer regions (A1 and A2); S1 and S2denote selected subpopulations of decamers from the original randomdecamer total populations; also shown is a head-to-tailchemically-ligated (non-amplifiable directly) click product resultingthrough RNA secondary structural spatially proximal hybridization.

FIGS. 52A, 52B, 52C, and 52D are representative diagrams showingpossible 5′ and 3′ structures for 5′-3′ click reactivity, where norequirement exists for polymerase read-through; 52A) representative5′-cycloalkyne and 5′-azide modifications; where polymerase read-throughis not required, a pair of 5′ and 3′-modified click-modifiedoligonucleotides can bear either cycloalkyne-azide combination of theabove representative modifications: for example, a pair ofoligonucleotides bearing the 5′ and 3′ structures represented by FIG.52A/C; 52B) representative 5′-cycloalkyne and 5′-azide modifications;where polymerase read-through is not required, a pair of 5′ and3′-modified click-modified oligonucleotides can bear eithercycloalkyne-azide combination of the above representative modifications:for example, a pair of oligonucleotides bearing the 5′ and 3′ structuresrepresented by FIG. 52B/D; 52C) representative 3′-cycloalkyne and3′-azide modifications; where polymerase read-through is not required, apair of 5′ and 3′-modified click-modified oligonucleotides can beareither cycloalkyne-azide combination of the above representativemodifications: for example, a pair of oligonucleotides bearing the 5′and 3′ structures represented by FIGS. 52A/C; and 52D) representative3′-cycloalkyne and 3′-azide modifications; where polymerase read-throughis not required, a pair of 5′ and 3′-modified click-modifiedoligonucleotides can bear either cycloalkyne-azide combination of theabove representative modifications: for example, a pair ofoligonucleotides bearing the 5′ and 3′ structures represented by FIG.52B/D.

FIGS. 53A and 53B are representative diagrams of regions ofsingle-stranded oligonucleotides with non-polymerase-readable 5′- and3′-click groups where modified for nuclease-resistance; shown bystippled background; 53A) non-modified regions are retained with normalDNA backbones and bases for allowing restriction enzyme cleavage; the 3′sites are extended by three modified-bases with modified backbones; 53B)non-modified regions are retained with normal DNA backbones and basesfor allowing restriction enzyme cleavage; the 3′ sites are extended bythree modified-bases with modified backbones.

FIG. 54 illustrates representative production of double-stranded 5′-3′chemical ligation products by polymerase extensions, and subsequentrecutting with restriction endonuclease Age I; S1 and S2 denote selectedsubpopulations of decamers from the original random decamer totalpopulations.

FIG. 55 shows representative partitioning of 5′-3′ chemically ligatedduplex products into in vitro microcompartments; here each fragment hasbeen initially cleaved with restriction enzyme E2 (Age I in thespecified embodiment).

FIG. 56 is a representative illustration of partitioning of unligated5′/3′-click-labeled duplex strands into microcompartments; here the5′-azide modified strand has been previously cleaved in the A2 regionwith restriction enzyme E2 (Age I in the specified embodiment).

FIG. 57 is a representative diagram of Xma I cutting (in the specifiedembodiment) and re-ligation of 5′-3′ linkages within microcompartments.

FIG. 58 shows representative cycling of Xma I cleaved (in the specifiedembodiment) 5′-3′ ligation products in microcompartments, untilirreversible and amplifiable rearrangement end-point is reached.

FIG. 59 depicts representative testing of the ability of in vitrocompartmentalization to enable molecule-specific rearrangements, foramplification and identification of specific sequences; step 1.validation model: make 4×oligonuceotides, two with 5′-azides, and twowith 5′ linear alkynes (joinable by Cu(I) mediated click chemistry);each designed with specific marker sequences, and to enable differentialamplifications.

FIG. 60 depicts representative demonstration of enzymatic rearrangementprocess for 5′-5′ oligonucleotide joins; product of the expected size isonly formed when both cutting and religation are applied; closelysimilar rearrangements enable amplification of 3′-3′ or “unreadable”5′-3′ joins.

FIG. 61 depicts representative testing of purified Top band 5′-5′chemical ligation adducts (from excised gel bands), run side-by-sidewith samples of corresponding unpurified material.

FIG. 62 depicts representative testing use of enzymes (Age I, Xma I, T4DNA ligase) designed to enable amplifiable products with all model Topband 5′-5′ adduct products.

FIG. 63 depicts representative principle of the model oligonucleotidedetection system for successful IVC; in this case, duplexed 5′-5′adducts are precut Age I for testing in IVC, such that only Xma I andligase are needed to complete the rearrangements.

FIG. 64 depicts representative testing primers designed to detectspecific rearrangements, whether direct (single-molecule) or specificcross-overs; for mixtures of two different 5′-5′ products undergoing theenzymatic rearrangements, specific primer pairs must be able to identifyonly each direct product, or a specific cross-over product.

FIG. 65 depicts representative testing specificity ofrearrangement-directed primers with pre formed rearrangements withoutPCR-induced artefactual crossing-over; BH, FH=direct rearrangements BHand FH adducts respectively; BH+FH rearr=rearrangement process performedwith BH and FH products simultaneously present (thus allowing cross-overrearrangements); BH+FH Mix=BH and FH adduct rearrangements performedseparately, and then mixed together prior to PCR; BH+FH Age=BH and FHadducts cut with Age I only and mixed prior to PCR; co=no-templatecontrol.

FIG. 66 depicts representative nested PCR results of in vitrocompartmentalization test; no detectable cross-over products wereobserved (vertical white arrows).

FIG. 67 depicts representative CLOSE amplification of 5′-3′ joins, bymeans of circularization and inverse PCR; this applies directread-through is not possible owing to the formation of bulkynon-traceless products; a potential problem with this approach iscross-ligation between separate molecules (rather than circularization),which would scramble the correct information; this can be minimized byperforming the religation step at low concentrations.

DESCRIPTION

The present disclosure is directed to methods and kits for identifying,enriching, and evaluating templated assembly reactants.

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those skilled in the art will understand that the devices andmethods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present disclosure is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of any other embodiments.Such modifications and variations are intended to be included within thescope of the present disclosure.

All publications, patents and patent applications cited herein, whethersupra or infra, are hereby incorporated by reference in their entirety.As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural references unless the contentclearly dictates otherwise. The terms used in this disclosure adhere tostandard definitions generally accepted by those having ordinary skillin the art. In case any further explanation might be needed, some termshave been further elucidated below.

The term “about,” as used herein, refers to variations in a numericalquantity that can occur, for example, through measuring or handlingprocedures in the real world; through inadvertent error in theseprocedures; through differences in the manufacture, source, or purity ofcompositions or reagents, and the like. Typically, the term “about” asused herein means greater or lesser than the value or range of valuesstated by 1/10 of the stated values, e.g., ±10%. For instance, aconcentration value of about 30% can mean a concentration from 27% to33%. The term “about” also refers to variations that would be recognizedby one skilled in the art as being equivalent so long as such variationsdo not encompass known values practiced by the prior art. Each value orrange of values preceded by the term “about” is also intended toencompass the embodiment of the stated absolute value or range ofvalues. Whether or not modified by the term “about,” quantitative valuesrecited in the claims include equivalents to the recited values, e.g.,variations in the numerical quantity of such values that can occur, butwould be recognized to be equivalents by a person skilled in the art.

The phrases “active effector structure” and “effector structure” areused interchangeably herein and refer to the active portion of atemplated assembly product that triggers a desired effect.

The term “base,” as used herein, refers to a molecule containing apurine or pyrimidine group, or an artificial analogue, that forms abinding pair with another corresponding base via Watson-Crick orHoogsteen bonding interactions. Bases further contain groups thatfacilitate covalently joining multiple bases together in a polymer, suchas an oligomer. Non-limiting examples include nucleotides, nucleosides,peptide nucleic acid residues, or morpholino residues.

The terms “bind,” “binds,” “binding,” and “bound,” as used herein, referto a stable interaction between two molecules that are close to oneanother. The terms include physical interactions, such as chemical bonds(either directly linked or through intermediate structures), as well asnon-physical interactions and attractive forces, such as electrostaticattraction, hydrogen bonding, and van der Waals/dispersion forces.

The phrase “bioconjugation chemistry,” as used herein, refers to thechemical synthesis strategies and reagents that ligate common functionalgroups together under mild conditions, facilitating the modularconstruction of multi-moiety compounds.

As used herein, “chemically-ligated oligonucleotides spatially elicited”refers to pairs of oligonucleotides that have been chemically ligated asa consequence of their spatial proximity through hybridization to targetnucleic acid templates.

The phrase “effector partial moiety,” as used herein, refers to aportion of a templated assembly reactant that contributes to thechemical structure of the effector structure in a product formed bynucleic acid templated assembly. An effector partial moiety may be adistinct portion of the reactant, or may include or be comprised of partor all of the nucleic acid recognition moiety and/or theselectively-reactive moiety.

The terms “linker” and “spacer” are used interchangeable herein andrefer to a molecule adjacent to the oligonucleotide sequence in thetemplated assembly reactant. A linker can be an additionaloligonucleotide sequence, a peptide, a non-active portion of apeptidomimetic structure, a non-active portion of a drug, or otherbioactive compound that is less than 20 kDa. A linker may be comprisedof branched or unbranched covalently bonded molecular chain.

The phrase “non-traceless bio-orthogonal chemistry,” as used herein,refers to a reaction involving selectively-reactive moieties in whichpart or all of the structure of the selectively-reactive moieties isretained in the product structure.

The phrase “nucleic acid recognition moiety” as used herein refers to anoligonucleotide that facilitates sequence-specific binding to a targetnucleic acid. An example of a nucleic acid recognition moiety is anoligonucleotide sequence that binds to a target nucleic acid.

The terms “oligonucleotide sequences” and “oligomer,” are usedinterchangeably herein and refer to a molecule comprised of multipleunits where some or all of the units are bases capable of formingWatson-Crick or Hoogsteen base-pairing interactions, allowingsequence-specific binding to nucleic acids in a duplex or multiplexstructure. Non-limiting examples include oligonucleotides, peptidenucleic acid oligomers, and morpholino oligomers.

The phrase “pathogenic cell” as used herein can refer to a cell that iscapable of causing or promoting a diseased or an abnormal condition,such as a cell infected with a virus, a tumor cell, and a cell infectedwith a microbe, or a cell that produces a molecule that induces ormediates diseases that include, but are not limited to allergy,anaphylaxis, inflammation and autoimmunity.

The phrase “pharmaceutically acceptable” when used herein refers to amaterial that is not biologically or otherwise unacceptable that can beincorporated into a composition and administered to a patient withoutcausing unacceptable biological effects or interacting in anunacceptable manner with other components of the composition.

The phrase “pharmaceutically acceptable salt” means a salt prepared froma base or an acid which is acceptable for administration to a patient,such as a mammal (e.g., salts having acceptable mammalian safety for agiven dosage regime).

The term “salt” as used herein can include salts derived frompharmaceutically acceptable inorganic acids and bases and salts derivedfrom pharmaceutically acceptable organic acids and bases and theirderivatives and variants thereof.

The term “sample,” as used herein, refers to any system that templatedassembly reactants can be administered into, where nucleic acidtemplated assembly may occur. Non-limiting examples may include livingcells, fixed or preserved cells, whole organisms, tissues, tumors,lysates, or in vitro assay systems.

The phrase “selectively-reactive moiety” refers to the portion of atemplated assembly reactant that enables formation of product, such asthrough a chemical reaction with a corresponding templated assemblyreactant. For example, a selectively-reactive moiety can react readilywith a corresponding selectively-reactive moiety, but does not readilyreact with natural biomolecules.

The phrases “set of corresponding reactants” or “corresponding templatedassembly reactants” are referred to herein as templated assemblyreactants that come together on a single target template to take part ina templated assembly reaction.

In any embodiment herein, a “subject” can be a cell, in vitro, such as acell in culture, or in vivo within a living organism. In someembodiments, the subject can be a microorganism. In some embodiments,the subject can be a cell derived from or comprised in a sample obtainedfrom a larger organism. For example, the subject can be a cell comprisedin a sample obtained from an organism by a biopsy procedure, and themethod can be performed on it. In some embodiments, the subject can be aprogeny (by cell division) of a progenitor cell obtained from anorganism. A subject can also be a mammal. Examples of subjects caninclude but are not limited to, humans, horses, monkeys, dogs, cats,mice, rates, cows, pigs, goats and sheep. In some embodiments,“subjects” are generally human patients.

The term “superantigen,” as used herein, refers to an antigen that bindsto a broad subset of T cells that express a particular variable (V)region.

The phrase “traceless bio-orthogonal chemistry,” as used herein, refersto a reaction involving selectively-reactive moieties in which anaturally occurring bond, for example an amide, is formed by eliminationof part or all of the selectively-reactive moieties from the productstructure.

The phrase “target compartment” as used herein refers to a cell, virus,tissue, tumor, lysate, other biological structure, spatial region, orsample that contains target nucleic acid, or a different amount oftarget nucleic acids than a non-target compartment.

The phrases “target nucleic acid sequence” and “target nucleic acid” areused interchangeably and refer to a sequence of units or nucleic acidswhich are intended to act as a template for nucleic acid templatedassembly.

The phrases “templated assembly,” “templated assembly reaction” and“nucleic acid templated assembly” are used interchangeably herein andrefer to the synthesis of a product structure or structures on a targetnucleic acid, such that product formation can be facilitated bytemplated assembly reactants being assembled in proximity when bound tothe target nucleic acid.

The phrase “templated assembly ligation product,” as used herein, refersto the product structure or structures formed by interaction, binding orreaction of one or more nucleic acid templated assembly reactants.

The phrase “templated assembly reactant” as used herein refers to anoligonucleotide sequence that binds to a target nucleic acid in asequence-specific manner and participates in product formation during atemplated assembly reaction.

Also included herein are “derivatives” or “analogs” such as salts,hydrates, solvates thereof, or other molecules that have been subjectedto chemical modification and maintain the same biological activity orlack of biological activity, and/or ability to act as a templatedassembly reactant, or function in a manner consistent with a templatedassembly reactant.

Targeted template assembly produces desired chemical structures when inthe presence of one or more targets, such as specific nucleic acidsequences. The disclosed methods and kits allow identification,analysis, or discovery of specific genetic templates. The disclosedmethods and kits also identify the specific nucleic acid sequencestargeted by templated assembly to avoid off-target toxicity and enhancespecific reactivity. The disclosed methods and kits further enrich andevaluate specific nucleic acid sequences for template assembly. Byidentifying unique nucleic acid sequences for target cells, directedintervention can be focused on these specific cells, such as byself-destruction or immunotherapeutic destruction by other cells,without inducing toxicity against non-target cells, such as normalcells, that lack the template target.

The identification of templated assembly targets can include methods andkits for synthesizing templated assembly reactants, hybridizing thetemplated assembly reactants to target nucleic acids, performing atemplated assembly reaction, and identifying the target nucleic acidsthat hybridized with the templated assembly reactants.

The phrase “templated assembly reactant” as used herein refers to anoligonucleotide sequence that binds to a target nucleic acid in asequence-specific manner and participates in product formation during atemplated assembly reaction. The templated assembly reactants caninclude a nucleic acid recognition moiety, such as an oligonucleotidesequence. U.S. Application No. 61/831,133, which is incorporated hereinby reference in its entirety, discloses targeted templated assemblyreactants that include a nucleic acid recognition moiety, aselectively-reactive moiety, and a effector partial moiety to produce atargeted therapeutic. In the present disclosure, the templated assemblyreactants do not require, but may still include, an effector partialmoiety. The identification, analysis, or discovery of target nucleicacids does not require the production of an effector function, such asdisclosed in U.S. Application No. 61/831,133, so the presence of atleast a nucleic acid recognition moiety and a selectively-reactivemoiety are included in the templated assembly reactant. In someembodiments, a first population of templated assembly reactants and asecond population of corresponding templated assembly reactants aredisclosed, where the first population includes different oligonucleotidesequences or different libraries of oligonucleotide sequences than thesecond population. In some embodiments, a first population of templatedassembly reactants and a second population of corresponding templatedassembly reactants are disclosed, where the first population includesspecific oligonucleotide sequences and chemical modifications differingfrom the second population.

Oligonucleotide sequences may be synthesized by several methods known inthe art. Nucleotide-based oligonucleotide sequences may be synthesizedin solution or on a solid-phase using phosphoramidite chemistry. Peptidenucleic acids may also be synthesized in solution or on a solid phaseusing methods known in the art. Various methods of morpholino synthesiscould also be used. Any of the aforementioned types of oligonucleotidesequences may also be obtained fully synthesized from various commercialsources.

The oligonucleotide sequences may include sequences of base-pair formingunits, such as nucleic acids or nucleic acid analogues. Theoligonucleotide sequences may be made of multiple units where some orall of the units are bases capable of forming Watson-Crick or Hoogsteenbase-pairing interactions, allowing sequence-specific binding to targetnucleic acids in a duplex or multiplex structure.

The phrase “nucleic acid” is well known in the art. A “nucleic acid” asused herein will generally refer to a molecule (i.e., a strand) of DNA,RNA or a derivative or analog thereof, comprising a nucleotide. Anucleotide includes, for example, a naturally occurring purine orpyrimidine base found in DNA (e.g., an adenine “A,” a guanine “G,” athymine “T” or a cytosine “C”) or RNA (e.g., an A, a G, an uracil “U” ora C). The phrase “nucleic acid” or “RNA molecule” encompasses the terms“oligonucleotide” and “polynucleotide,” each as a subgenus of “nucleicacid.”

The oligonucleotide sequences may be DNA nucleotides, RNA nucleotides,phosphorothioate-modified nucleotides, 2′-O-alkylated RNA nucleotides,halogenated nucleotides, locked nucleic acid nucleotides (LNA), peptidenucleic acids (PNA), morpholino nucleic acid analogues (morpholinos),pseudouridine nucleotides, xanthine nucleotides, hypoxanthinenucleotides, 2′-deoxyinosine nucleotides, other nucleic acid analoguescapable of base-pair formation, or combinations thereof. In someembodiments, the oligonucleotide sequences includes nucleic acids andhybridizes to mRNA targets.

Commercially available derivatized bases may be incorporated tointroduce functional groups including but not limited to amines,hydrazides, thiols, carboxylic acids, isocyanates, aldehydes which maythen be conjugated with active functional groups on other moieties usingstandard techniques of bioconjugation chemistry to facilitate synthesisof the complete templated assembly reactant.

The oligonucleotide sequences may also incorporate, interact with or bebound to specialized units. For example, when using the templatedassembly reactants, including an oligonucleotide sequence, in thepresence of nucleases that may degrade standard DNA or RNA, such as inlive cells or lysates, it may be desirable to incorporatenuclease-resistant bases into the oligonucleotide sequences. Somenon-limiting examples can include phosphorothioate bases, 2′-O-alkylatedor 2′-halogenated RNA bases, locked nucleic acids, peptide nucleicacids, morpholinos or a chimera including at least one of these. Unlikeantisense probes that depend on RNase H activity, internal bases of theoligomer need not induce RNase H hydrolysis of a target RNA transcript.Thus, there is no requirement for RNase H-inducing bases at any positionin the oligonucleotide sequence.

The templated assembly reactants can be synthesized to includeoligonucleotide sequences that are random sequences or gene specificsequences. In some embodiments, the templated assembly reactants canbind to a target nucleic acid through a gene specific oligonucleotidesequence. The oligonucleotide sequences can be contiguous ornon-contiguous sequences complementary to one or more target nucleicacids. The phrases “target nucleic acid sequence” and “target nucleicacid” are used interchangeably and refer to a sequence of units ornucleic acids which are intended to act as a target or template fornucleic acid templated assembly.

The oligonucleotide sequences can be gene specific by beingcomplementary to a hybridization site on a target nucleic acid, allowingsequence-specific binding to the target nucleic acid. In someembodiments, the oligonucleotide sequence is a contiguous sequence thatis complementary to a target nucleic acid. In some embodiments, theoligonucleotide sequence is selected such that its sequence is notsimilar to sequences known to be present in non-target nucleic acids. Insome embodiments, the oligonucleotide sequence includes one or moremutations found within the target nucleic acid, allowing specificbinding of the templated assembly reactants to the target nucleic acidsbut not to non-target nucleic acids that do not contain the mutation. Insome embodiments, the oligonucleotide sequence may be synthesized with astem-loop structure, with possible improvement in the desired bindinginteraction with target nucleic acids.

The oligonucleotide sequences can also be random sequences. The randomoligonucleotide sequences can include any of the above base-pair formingunits or specialized units in a random sequence.

The oligonucleotide sequences can be from about 5 to about 100nucleotides long. In some embodiments, the random or gene specificsequence can be about 5 to about 100 nucleotides long. Theoligonucleotides sequences can be any of 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49,50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67,68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85,86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100nucleotides long. In some embodiments, the oligonucleotides sequencescan be from about 5 to about 30 nucleotides long, from about 7 to about25 nucleotides long, or from about 7 to about 15 nucleotides long.

The oligonucleotide sequences, whether random or gene specific, can becomplementary to a target nucleic acid with a length of theoligonucleotide sequence anywhere from about 5 to about 100 bases inlength. In some embodiments, the oligonucleotide sequences can becomplementary to the target nucleic acid with an oligonucleotidesequence length in the range of about 5 to about 50 bases in length,about 5 to about 40 bases in length, or about 10 to about 30 bases inlength.

The oligonucleotide sequences can also be optimized to provide chemicalproperties. The length of oligonucleotide sequences can be selectedbased on chemical properties, such as melting and annealing temperaturesof the complementary sequence. The melting temperature, T_(m), isdefined as the temperature in degrees Celsius, at which 50% of allmolecules of a given oligonucleotide sequences are hybridized into adouble strand, and 50% are present as single strands. The annealingtemperature is generally 5 C lower than the melting temperature.

The T_(m) of the oligonucleotide sequences can be in a range from about10 C below to about 40 C above the temperature of the conditions inwhich the templated assembly reactant will be used. For example, iftemplated assembly reactants are to be used at 37 C, the oligonucleotidemay be designed with an expected T_(m) from 27 C to 77 C. In someembodiments, the template assembly reactants can be used atapproximately 37 C, and the T_(m) of the oligonucleotide sequences canbe designed to be in the range of about 37 C to about 52 C.

In some embodiments, oligonucleotide sequences can be designed such thatthe T_(m) to bind the target nucleic acid is substantially differentfrom the T_(m) to bind a similar non-target nucleic acid. For example,the oligonucleotide sequences may be designed such that thehybridization site it binds to on a target nucleic acid includes thesite of a mutation. In some embodiments, the T_(m) of theoligonucleotide sequences binding to the target nucleic acid is at orabove the temperature at which the templated assembly reactant will beused, while the T_(m) of the oligonucleotide sequences binding to thenon-target nucleic acid is below the temperature at which the templatedassembly reactant will be used. The oligonucleotide sequences will thenbind to the mutant target sequence, but not to the non-target,non-mutant sequence.

The T_(m) of the oligonucleotide sequences can be in a range from about10 C below to about 40 C above the temperature of the conditions inwhich the templated assembly reactant will be used. For example, iftemplated assembly reactants are to be used at 37 C, the oligonucleotidesequences may be designed with an expected T_(m) from 27 C to 77 C. Insome embodiments, the template assembly reactants can be used atapproximately 37 C, and the T_(m) of the oligonucleotide sequences canbe designed to be in the range of about 37 C to about 52 C.

The templated assembly reactant can also include a 5′ and/or a 3′priming site adjacent to the oligonucleotide sequences. The priming sitecan be directly flanking the oligonucleotide sequence or can beseparated from the oligonucleotide sequence by a linker sequence. Primersequences commonly used in the art can be included. Such examples mayinclude, but are not limited to, M13, T3, T7, SP6, VF2, VR, modifiedversions thereof, complementary sequences thereof, and reverse sequencesthereof. In addition, custom primer sequences are also included.

The templated assembly reactants can also include an intermediate, suchas a linker or spacer. The linker can be an additional oligonucleotidesequence ranging from 1 to about 50 nucleotides long. The linker canalso be a peptide, a non-active portion of a peptidomimetic structure, anon-active portion of a drug, or other bioactive compound that is lessthan 20 kDa. A linker may be comprised of branched or unbranchedcovalently bonded molecular chain. In some embodiments, the linker is aspacer of at least 6 carbon atoms.

The templated assembly reactants can also include a modificationadjacent to the oligonucleotide sequences to be reactive in a templatedassembly reaction, such as a selectively-reactive moiety. Suchmodifications for templated assembly reactions are disclosed in U.S.Application No. 61/831,133, which is incorporated herein by reference inits entirety. In some embodiments, the modification is flanking theoligonucleotide sequence. As used herein, the “flanking sequence” canrefer to a region immediately, e.g. within 1 to 5 basepairs, or withinclose proximity to, e.g. within 5 to 20 basepairs, the oligonucleotidesequence.

The modification can be biologically inert. In particular, themodification on one oligonucleotide sequence can interact readily with acorresponding modification on another oligonucleotide sequence, but willnot readily interact with natural biomolecules. This is to ensure thatthe templated assembly reaction is formed when corresponding templatedassembly reactants are assembled. It also safeguards againstnon-specific reactions occurring in the environment and prevents theformation of unintended products.

Examples of selectively-reactive moieties, modifications for reactivityin a templated assembly reaction, can include adding a bio-orthogonalreactive moiety. The bio-orthogonal reactive moiety can include thosegroups that can undergo “click” reactions between azides and alkynes,traceless or non-traceless Staudinger reactions between azides andphosphines, and native chemical ligation reactions between thioestersand thiols. Additionally, the bio-orthogonal moiety can be any of anazide, a cyclooctyne, a nitrone, a norbornene, an oxanorbornadiene, aphosphine, a dialkyl phosphine, a trialkyl phosphine, a phosphinothiol,a phosphinophenol, a cyclooctene, a nitrile oxide, a thioester, atetrazine, an isonitrile, a tetrazole, a quadricyclane, and derivativesthereof.

In some embodiments, a first population of templated assembly reactantsand a second population of corresponding templated assembly reactantsare disclosed. The first population can include one modification and thesecond population can include a corresponding modification. For example,the first population can include azides on the templated assemblyreactants and the second population can include alkynes on the templatedassembly reactants, such that the first and second populations arecapable of reacting in a click reaction to produce ligated products.

Multiple modifications for reactivity in a templated assembly reactioncan be used with the methods and kits disclosed herein, somenon-limiting examples include:

Azide-alkyne “Click Chemistry”: click chemistry is highly selective asneither azides nor alkynes react with common biomolecules under typicalconditions. Azides of the form R—N₃ and terminal alkynes of the formR—C≡CH or internal alkynes of the form R—C≡C—R react readily with eachother to produce Huisgen cycloaddition products in the form of1,2,3-triazoles

Azide-based templated assembly reactants have the substructure: R—N₃where R is a chemical linker, nucleic acid recognition moiety, oreffector partial moiety. Azides and azide derivatives may be readilyprepared from commercially available reagents.

Azides can also be introduced to an effector partial moiety duringsynthesis of the effector partial moiety. In some embodiments, an azidegroup is introduced into a effector partial moiety comprised of apeptide by incorporation of a commercially available azide-derivatizedstandard amino acid or amino acid analogue during synthesis of theeffector partial moiety peptide using standard peptide synthesismethods. Amino acids may be derivatized with an azide replacing theα-amino group, affording a structure of the form:

where R is a side chain of a standard amino acid or non-standard aminoacid analogue.

Commercially available products can introduce azide functionality as anamino acid side chains, resulting in a structure of the form:

where A is any atom and its substituents in a side chain of a standardamino acid or non-standard amino acid analogue.

An azide may also be introduced into a effector partial moiety peptideafter synthesis by conversion of an amine group on the peptide to anazide by diazotransfer methods. Bioconjugate chemistry can also be usedto join commercially available derivatized azides to chemical linkers,nucleic acid recognition moieties, or effector partial moieties thatcontain suitable reactive groups.

Standard alkynes can be incorporated into a templated assembly reactantby methods similar to azide incorporation. Alkyne-functionalizednucleotide analogues are commercially available, allowing alkyne groupsto be directly incorporated at the time of nucleic acid recognitionmoiety synthesis. Similarly, alkyne-derivatized amino acid analogues maybe incorporated into a effector partial moiety by standard peptidesynthesis methods. Additionally, diverse functionalized alkynescompatible with bioconjugate chemistry approaches may be used tofacilitate the incorporation of alkynes to other moieties throughsuitable functional or side groups.

Azide-activated alkyne “Click Chemistry”: Standard azide-alkynechemistry reactions typically require a catalyst, such as copper(I).Since copper(I) at catalytic concentrations is toxic to many biologicalsystems, standard azide-alkyne chemistry reactions have limited uses inliving cells. Copper-free click chemistry systems based on activatedalkynes circumvent toxic catalysts.

Activated alkynes often take the form of cyclooctynes, whereincorporation into the cyclooctyl group introduces ring strain to thealkyne

Heteroatoms or substituents may be introduced at various locations inthe cyclooctyl ring, which may alter the reactivity of the alkyne orafford other alternative chemical properties in the compound. Variouslocations on the ring may also serve as attachment points for linkingthe cyclooctyne to a nucleic acid templated assembly moiety or linker.These locations on the ring or its substituents may optionally befurther derivatized with accessory groups.

Multiple cyclooctynes are commercially available, including severalderivatized versions suitable for use with standard bioconjugationchemistry protocols. Commercially available cyclooctyne derivatizednucleotides can aid in facilitating convenient incorporation of theselectively-reactive moiety during nucleic acid recognition moietysynthesis

Cyclooctyne-azide based bio-orthogonal chemistry may produce templatedassembly products of the general structure:

Another example:

Azide-Phosphine Staudinger Chemistry: The Staudinger reduction, based onthe rapid reaction between an azide and a phosphine or phosphite withloss of N₂, also represents a bio-orthogonal reaction. The Staudingerligation, in which covalent links are formed between the reactants in aStaudinger reaction, is suited for use in nucleic acid templatedassembly. Both non-traceless and traceless forms of the Staudingerligation allow for a diversity of options in the chemical structure ofproducts formed in these reactions.

Non-Traceless Staudinger Ligation: The standard Staudinger ligation is anon-traceless reaction between an azide and a phenyl-substitutedphosphine such as triphenylphosphine, where an electrophilic trapsubstituent on the phosphine, such as a methyl ester, rearranges withthe aza-ylide intermediate of the reaction to produce a ligation productlinked by a phosphine oxide. An example of a Staudinger ligation productformed by templated assembly reactants A and B may have the structure:

Phenyl-substituted phosphines carrying electrophilic traps can also bereadily synthesized. Derivatized versions are available commercially andsuitable for incorporation into templated assembly reactants:

Traceless Staudinger Ligation: In some embodiments, phosphines capableof traceless Staudinger ligations may be utilized asselectively-reactive moieties. In a traceless reaction, the phosphineserves as a leaving group during rearrangement of the aza-ylideintermediate, creating a ligation typically in the form of a nativeamide bond. Compounds capable of traceless Staudinger ligation generallytake the form of a thioester derivatized phosphine or an esterderivatized phosphine:

Ester derivatized phosphines for traceless Staudinger ligation.

Thioester derivatized phosphines for traceless Staudinger ligations.

Chemical linkers or accessory groups may optionally be appended assubstituents to the R groups in the above structures, providingattachment points for nucleic acid recognition moieties or for theintroduction of additional functionality to the reactant.

Traceless Phosphinophenol Staudinger Ligation: Compared to thenon-traceless Staudinger phenylphosphine compounds, the orientation ofthe electrophilic trap ester on a traceless phosphinophenol is reversedrelative to the phenyl group. This enables traceless Staudingerligations to occur in reactions with azides, generating a native amidebond in the product without inclusion of the phosphine oxide

The traceless Staudinger ligation may be performed in aqueous mediawithout organic co-solvents if suitable hydrophilic groups, such astertiary amines, are appended to the phenylphosphine. An article byWeisbord and Marx (2010) describes preparation of water-solublephosphinophenol, which may be loaded with a desired effector partialmoiety containing a carboxylic acid (such as the C-terminus of apeptide) via the mild Steglich esterification using a carbodiimide suchas dicyclohexylcarbodiimide (DCC) or N,N′-diisopropylcarbodiimide (DIC)and an ester-activating agent such as 1-hydroxybenzotriazole (HOBT).This approach facilitates synthesis of templated assembly reactants ofthe form:

Water-soluble phosphinophenol-based traceless templated assemblyreactant structure.

Traceless Phosphinomethanethiol Staudinger Ligation:Phosphinomethanethiols represent an alternative to phosphinophenols formediating traceless Staudinger ligation reactions. In general,phosphinomethanethiols possess favorable reaction kinetics compared withphosphinophenols in mediating traceless Staudinger reaction. U.S.Application 2010/0048866 and an article to Tam et al. (2007) describepreparation of water-soluble phosphinomethanethiols of the form:

These compounds may be loaded with a peptide or other payload, in theform of an activated ester, to form a thioester suitable for use as atraceless bio-orthogonal reactive group:

Templated assembly reactant structure based on water-solublephosphinomethanethiol traceless Staudinger bio-orthogonal chemistry.

Native Chemical Ligation: Native chemical ligation is a bio-orthogonalapproach based on the reaction between a thioester and a compoundbearing a thiol and an amine. The classic native chemical ligation isbetween a peptide bearing a C-terminal thioester and another bearing anN-terminal cysteine, as seen below:

Native chemical ligation may be utilized to mediate traceless reactionsproducing a peptide or peptidomimetic containing an internal cysteineresidue, or other thiol-containing residue if non-standard amino acidsare utilized.

N-terminal cysteines may be incorporated by standard amino acidsynthesis methods. Terminal thioesters may be generated by severalmethods known in the art, including condensation of activated esterswith thiols using agents such as dicyclohexylcarbodiimide (DCC), orintroduction during peptide synthesis via the use of “Safety-Catch”support resins.

Other Templated Assembly Reaction Moieties: Any suitable bio-orthogonalreaction chemistry may be utilized for synthesis of templated assemblyreactants, as long as it efficiently mediates a reaction in a highlyselective manner in complex biologic environments. A recently developednon-limiting example of an alternative bio-orthogonal chemistry that maybe suitable is reaction between tetrazine and various alkenes such asnorbornene and trans-cyclooctene, which efficiently mediatesbio-orthogonal reactions in aqueous media.

In some embodiments, the templated assembly reactants can also includean effector partial moiety, such that when a set of correspondingtemplated assembly reactants participates in a templated assemblyreaction, an active effector product can be generated. The effectorpartial moiety can be a portion of an active effector structure, suchthat when a set of corresponding templated assembly reactants take partin a templated reaction, their effector partial moieties combine toproduce the desired active effector structure in the templated assemblyligation product. Thus, the effector partial moiety contributes to thechemical structure of the active effector structure. The effectorpartial moiety can be a distinct portion of the templated assemblyreactant, or may include part or all of the nucleic acid recognitionmoiety and/or part or all of the selectively-reactive moiety. Thephrases “active effector structure” and “effector structure” are usedinterchangeably herein and refer to the active portion of a templatedassembly product that triggers a desired effect.

The effector partial moiety does not possess the targeted activity orthe same level of activity associated with the active effectorstructure. In some embodiments, the effector partial structure issubstantially inactive as compared to the active effector structure. Insome embodiments, the individual effector partial moieties can possessseparate activity, but binding the effector partial moieties togethercreate an activity not possessed by them individually. For example, abivalent effector structure that binds two different antibodies (eachbinds to a effector partial structure), making the effector suitablee.g., for detection in a sandwich ELISA for diagnostic evaluation. Insome embodiments, the effector partial moieties together create a signalthat can be detected upon a templated assembly reaction, such asluminescence.

The identification of templated assembly targets can include hybridizingthe templated assembly reactants to target nucleic acids.

Nucleic acids, such as DNA or RNA, from a source of interest can behybridized with the templated assembly reactants to selectively bind theoligonucleotide sequences. A target nucleic acid “complement(s)” or is“complementary” to the oligonucleotide when it is capable ofbase-pairing with the oligonucleotide according to the standardWatson-Crick, Hoogsteen or reverse Hoogsteen binding complementarityrules.

As used herein, the terms “complementary” and “complement(s)” refer toan oligonucleotide comprising a sequence of consecutive nucleotides orsemi-consecutive nucleotides (e.g., one or more nucleotide moieties arenot present in the molecule) capable of hybridizing to a target nucleicacid strand or duplex that may be consecutive, semi-consecutive ornon-consecutive nucleotides even if less than all the nucleotides do notbase pair with a counterpart nucleotide. In some embodiments, a“complementary” nucleic acid comprises a sequence in which about 70%,about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about77%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%,about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%,about 96%, about 97%, about 98%, about 99%, to about 100%, and any rangederivable therein, of the oligonucleotide sequence is capable ofbase-pairing with a single or double stranded target nucleic acid duringhybridization. In some embodiments, the term “complementary” refers toan oligonucleotide that may hybridize to target nucleic acid strand orduplex in stringent conditions, as would be understood by one ofordinary skill in the art.

In some embodiments, a “partly complementary” nucleic acid comprises asequence that may hybridize in low stringency conditions to a single ordouble stranded nucleic acid, or contains a sequence in which less thanabout 70% of the nucleotide sequence is capable of base-pairing with asingle or double stranded nucleic acid molecule during hybridization.

Prior to hybridization, the oligonucleotides modified to nucleic acidtemplate reactants are subjected to a transient heat-denaturation step(2 minutes/80° C.). The samples are exposed to conditions conducive forhybridization to accessible tracts of target nucleic acids bycomplementary oligonucleotides.

Any nucleic acid can be a possible target nucleic acid for nucleic acidtemplated assembly provided that at least some sequence information isavailable, sufficient to bind the oligonucleotide either directly orindirectly. Some non-limiting examples of nucleic acid recognitionmoiety units can include oligonucleotides, peptide nucleic acidoligomers, and morpholino oligomers. Some non-limiting examples oftarget nucleic acid sequences or oligonucleotides can include mRNA,genomic or organellar DNA, episomal or plasmid DNA, viral DNA or RNA,miRNA, rRNA, snRNA, tRNA, or any other biological or artificial nucleicacid sequence.

In some embodiments, the target nucleic acid can be present in a targetcompartment but absent in a non-target compartment. An example of thisembodiment includes nucleic acid sequences present in a pathogenic ordiseased cell, but absent in a healthy cell. The phrase “pathogeniccell” as used herein can refer to a cell that is capable of causing orpromoting a diseased or an abnormal condition, such as a cell infectedwith a virus, a tumor cell, and a cell infected with a microbe.

Any cell, virus, tissues, spatial regions, lysate, or other subcomponentof a sample that contains a target nucleic acid can provide the targetnucleic acid. Target compartments that contain the target nucleic acidcan include, but are not limited to, pathogenic cells, cancer cells,viruses, host cells infected by a virus or other pathogen, or cells ofthe immune system that are contributing to autoimmunity such as cells ofthe adaptive or innate immune systems, transplant rejection, or anallergic response. In some embodiments, a target nucleic acid can bepresent in a virus or cell infected by a virus, but absent in healthycells. Some non-limiting examples of virus can include DNA viruses, RNAviruses, or reverse transcribing viruses. In some embodiments, a targetnucleic acid can be present in a tumor or cancerous cell, but absent inhealthy cells. Some non-limiting examples of cancers can include thosecaused by oncoviruses, such as the human papilloma viruses, Epstein-Barrvirus, hepatitis B virus, hepatitis C virus, human T-lymphotropicviruses, Merkel cell polyoma virus, and Kaposi's sarcoma-associatedherpesvirus. In some embodiments, a target nucleic acid can be presentin an infectious agent or microbe, or a cell infected by an infectiousagent or microbe but is absent in healthy cells. Some non-limitingexamples of infectious agents or microbes can include viruses, bacteria,fungi, protists, prions, or eukaryotic parasites.

The target nucleic acid sequence can also be a fragment, portion or partof a gene, such as an oncogene, a mutant gene, an oncoviral gene, aviral nucleic acid sequence, a microbial nucleic acid sequence, adifferentially expressed gene, and a nucleic acid gene product thereof.

Some non-limiting examples of virus-specific target nucleic acids caninclude sequences present in DNA viruses, RNA viruses, or reversetranscribing viruses. Some non-limiting examples of cancer-specificnucleic acids can include sequences derived from oncoviruses, including,but not limited to, human papilloma virus, Epstein-Barr virus, hepatitisB virus, hepatitis C virus, human T-lymphotropic virus, Merkel cellpolyoma virus, and Kaposi's sarcoma-associated herpesvirus. Examples ofcancer-specific target nucleic acids can include mutant oncogenes, suchas mutated ras, HRAS, KRAS, NRAS, BRAF, EGFR, FLT1, FLT4, KDR, PDGFRA,PDGFRB, ABL1, PDGFB, MYC, CCND1, CDK2, CDK4, or SRC genes; mutant tumorsuppressor genes, such as TP53, TP63, TP73, MDM1, MDM2, ATM, RB1, RBL1,RBL2, PTEN, APC, DCC, WT1, IRF1, CDK2AP1, CDKN1A, CDKN1B, CDKN2A, TRIM3,BRCA1, or BRCA2 genes; and genes expressed in cancer cells, where thegene may not be mutated or genetically altered, but is not expressed inhealthy cells of a sample at the time of administration, such ascarcinoembryonic antigen.

The target nucleic acids can be obtained prior to hybridizing theoligonucleotides in the templated assembly reactants to the targetnucleic acids. The target nucleic acids can further be isolated from atarget sample, such as a cell population, a tumor, a tissue, or anorgan. The target nucleic acids can also be present in a whole celllysate and not separated or isolated other cellular materials. In someembodiments, the native secondary structures of the target nucleic acidsis maintained prior to hybridization.

In some embodiments, the target nucleic acid can be present indifferential amounts or concentrations in the target compartments ascompared to the non-target compartments. Examples can include, but arenot limited to, genes expressed at a different level in cancer cellsthan in healthy cells, such as myc, telomerase, HER2, orcyclin-dependent kinases. In some embodiments, the target nucleic acidsequence can be a gene that is at least 1.5×-fold or 2.0×-folddifferentially expressed in the target versus the non-targetcompartments. Some examples of these can include, but are not limitedto, genes related to mediating Type I allergic responses, for whichtarget RNA molecules contain immunoglobulin epsilon heavy chainsequences; genes expressed in T cell subsets, such as specific T cellreceptors (TCRs) which recognize self-antigens in the context ofparticular major histocompatibility (MHC) proteins likeproinsulin-derived peptide and clonally-specific mRNAs containing α or βvariable-region sequences, derived from diabetogenic CD8+ T cells; andcytokines whose production may have adverse outcomes throughexacerbation of inflammatory responses, including but not limited toTNF-alpha, TNF-beta, IL-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-15,IL-17, IL-18, IL-21, IL-22, IL-27, IL-31, IFN-gamma, OSM, and LIF.

In some embodiments, a target nucleic acid is present in targetcompartments and an acceptable subgroup of non-target compartments, butnot in a different or distinct subgroup of non-target compartments. Somenon-limiting examples can include genes expressed in cancer cells andlimited to classes of healthy cells, such as cancer-testis antigens,survivin, prostate-specific antigen, carcinoembryonic antigen (CEA),alpha-fetoprotein and other onco-fetal proteins. Also, many tissues andorgans are not essential to otherwise healthy life in the face ofserious disease. For example, melanocyte antigens, such asMelan-A/MART-1 and gp100 are expressed on many malignant melanomas aswell as normal melanocytes, and therapies that target these antigens candestroy both tumors and normal melanocytes, resulting in vitiligo, butmajor tumor reduction. Likewise, the reproductive organs may besurgically removed, such as testis, ovary and uterus, as well asassociated organs such as breast and prostate may be targeted whentumors of these tissues arise, and destruction of normal tissues withinthese organs may be a tolerable consequence of therapy. Furthermore,some cells that produce hormones, such as thyroxine and insulin can bereplaced with the relevant peptide or protein, allowing potentialtargeting of normal cells that may exist in the presence of tumors ofthese origins.

Target nucleic acids can also include novel sequences, not previouslyidentified. In some embodiments, a sample or samples can be evaluated bysequence analysis, such as next-generation sequencing,whole-transcriptome (RNA-seq) or whole-genome sequencing, microarrayprofiling, serial analysis of gene expression (SAGE), to determine thegenetic makeup of the sample. Target nucleic acid sequences can beidentified as those present in target compartments, but not present innon-target compartments, or present in differential amounts orconcentrations in target compartments as compared to non-targetcompartments. Sequences identified by this method can then serve astarget nucleic acids.

The oligonucleotide sequence of the templated assembly reactant canhybridize under hybridization conditions with varying stringency. Thephrase “hybridization conditions” refers to conditions under which theoligonucleotides will hybridize to its target nucleic acids, typicallyin a complex mixture of nucleic acids, such as whole cell lysates, butto no other sequences. Hybridization conditions are sequence dependentand will be different in different circumstances. Longer sequenceshybridize specifically at higher temperatures. An extensive guide to thehybridization of nucleic acids is found in Tijssen, Techniques inBiochemistry and Molecular Biology—Hybridisation with Nucleic Probes,“Overview of principles of hybridization and the strategy of nucleicacid assays” (1993). Generally, hybridization conditions are selected tobe about 5-10 C lower than the thermal melting point (T_(m)) for thespecific sequence at a defined ionic strength pH. The T_(m) is thetemperature (under defined ionic strength, pH, and nucleicconcentration) at which 50% of the oligonucleotides complementary to thetarget hybridize to the target nucleic acids at equilibrium (as thetarget nucleic acids are present in excess, at T_(m), 50% of the probesare occupied at equilibrium).

The templated assembly reactants with oligonucleotide sequences can bepresent in an excess over the target nucleic acids during hybridization.In some embodiments, the oligonucleotides can be present in about a10-100 fold excess over the target nucleic acids. The oligonucleotidescan be about 5×, 10×, 15×, 20×, 25×, 30×, 35×, 40×, 45×, 50×, 55×, 60×,65×, 70×, 75×, 80×, 85×, 90×, 95×, 100×, 125×, 150×, 200×, 300×, or anyamount in between, excess over the target nucleic acids.

While excess of templated assembly reactants with oligonucleotidesequences (effector partials) over target templates is permissable, theconverse situation (excess of target template) may reduce templatedassembly efficacy. This “template titration” effect indicates thatquantitation of template levels is highly useful, as well asidentification of suitable specific sites within an RNA target molecule.Very low levels of an RNA target may also be counter-productive in termsof the application of templated assembly. Thus, an ideal range may existfor a specific template, influenced by steady-state template levels andother factors, including efficiency of target site access.

Hybridization conditions can be those in which the salt concentration isless than about 1.0 M sodium ion, typically about 0.01 to 1.0 M sodiumion concentration (or other salts) at pH 7.0 to 8.3 and the temperatureis at least about 30 C for short probes (e.g., 10 to 50 nucleotides) andat least about 60 C for long oligonucleotides (e.g., greater than 50nucleotides). Hybridization conditions may also be achieved with theaddition of destabilizing agents such as formamide. For selective orspecific hybridization, a positive signal is at least two timesbackground, optionally 10 times background hybridization. Exemplaryhybridization hybridization conditions can be as following: 50%formamide, 5×SSC, and 1% SDS, incubating at 42 C, or, 5×SSC, 1% SDS,incubating at 65 C, with wash in 0.2×SSC, and 0.1% SDS at 65 C. Suchhybridizations and wash steps can be carried out for, e.g., 5, 10, 15,30, 60, 90, or more minutes. In an exemplary embodiment, suchhybridizations and wash steps can be carried out for periods of 2-16hours.

Excess unbound templated assembly reactants can also be removed afterhybridization. The unbound templated assembly reactants can be removedby methods commonly used in the art, such as but not limited to,enzymatic digestion, ultrafiltration, or gel size-exclusionchromatography.

Hybridizations can also be performed successively. In some embodiments,a first population of templated assembly reactants is hybridized to thetarget nucleic acids. Excess unbound templated assembly reactants of thefirst population can be removed. Then the second population ofcorresponding templated assembly reactants can be hybridized to thetarget nucleic acids that have been hybridized to the first population.Excess unbound templated assembly reactants of the second population canalso be removed.

Nucleic acid templated assembly brings two or more templated assemblyreactants into proximity to generate a templated assembly ligationproduct. The phrase “templated assembly ligation product,” as usedherein, refers to the product structure or structures formed byinteraction, binding or reaction of one or more nucleic acid templatedassembly reactants. A templated assembly ligation product may include anactive effector product capable of producing a desired biologicalactivity. Templated assembly ligation product formation is facilitatedby the individual templated assembly reactants being assembled in aposition- and/or orientation-specific manner through bindinginteractions, such as hybridization and annealing, with a target nucleicacid. Templated assembly reactants that come together on a single targettemplate to take part in a templated assembly reaction are referred toherein as a “set of corresponding reactants” or “corresponding templatedassembly reactants.” A set of corresponding templated assembly reactantsbind in a sequence-specific manner to spatially proximate parts of anucleic acid target template, and readily react with each other toproduce templated assembly ligation products including an activeeffector structure.

The templated assembly reaction can be, but is not limited to thefollowing reactions: a click chemical reaction, a Staudinger chemistry,a non-traceless Staudinger ligation, traceless Staudinger ligation, anative chemical ligation, and other template assembly reactions. In someembodiments, the templated assembly reaction can be either a tracelessphosphinophenol Staudinger ligation or a traceless phosphinomethanethiolStaudinger ligation. In some embodiments, click reactions can beperformed.

Templated assembly reactions are further disclosed in U.S. ApplicationNo. 61/831,133, which is incorporated herein by reference in itsentirety.

Excess unbound templated assembly reactants can also be removed aftertemplated assembly. The unbound templated assembly reactants can beremoved by methods commonly used in the art, such as but not limited to,enzymatic digestion, ultrafiltration, or gel size-exclusionchromatography.

Identifying the target nucleic acids can include any, or a combinationof, amplifying the reacted or unreacted templated assembly reactants;selective cleavage of reacted or unreacted templated assembly reactants;microcompartmentalizing the reacted templated assembly reactants fromthe unreacted templated assembly reactants; and sequencing theoligonucleotides from the reacted templated assembly reactants.

Identification of the target nucleic acids can be performed byamplification of the complementary reacted templated assembly (CLOSE)reactants with primers complementary to the priming sites carried by thespecific oligonucleotides. Only templated assembly reactant pairs (onefrom each separately-modified population) that have chemically joinedvia specific templated assembly reaction with the formation of triazoleproduct are potentially amplifiable by PCR, by virtue of the specificlinkage produced between the reactants.

In addition to effector partial sites for templated assembly that arecontiguous within a target RNA sequence, non-contiguous (discontinuous)target sites may be effective, provided that they are brought intospatial proximity by virtue of folded RNA secondary structures, or otherhigh-order structural arrangements. Non-limiting examples of suchsecondary structural motifs include stem loops, internal sites withinloops, and pseudoknots.

Oligonucleotides from the templated assembly reactants may hybridize totarget nucleic acids in a spatially-proximal manner, yet be unable topromote amplifiable templated assembly reaction linkages. This may occurwhen the hybridizations juxtapose non-biologically amplifiable 5′-5′ or3′-3′ ends, or where the templated assembly reaction between 5′- and3′-modified ends of the template assembly reactants results in productswhose size or structure is incompatible with polymerases.

Selective cleavage of the reacted templated assembly reactants, orreacted products, can also be performed. Restriction digestion ofreacted products over unreacted products can utilize sites engineeredinto primer sites or linker sequences adjacent to the oligonucleotidesequences. Reacted and unreacted products can also be differentiated bymethylation specific enzymes. In some embodiments, cleavage enzymes thatare sensitive to 5-methylcytosine hemimethylation can be used. In someembodiments, the reacted products can be made double stranded throughpolymerase extension. The resulting duplex can be cleaved with an enzymethat recognizes a restriction site in the primer sites or linkersequences.

The cleaved reacted products can also be enzymatically ligated topreserve the linkage information between proximally-hybridized sequencesand enable amplification.

In vitro compartmentalization can also be used to isolate templatedassembly reaction linkages relies from unreacted templated assemblyreactants by sequestering unreacted strands into individually-isolatedcompartments, preventing their ligation or reaction with other unreactedstrands that may give spurious amplification signals (signals which havenot resulted from original templated assembly reactions). Theseconditions can be achievable by forming emulsions which may be producedfrom any suitable combination of immiscible liquids. Hydrophilicsolvents form “aqueous” droplets of microscopic or colloidal size.“Droplets” are also referred to as “microcompartments” herein. Theaqueous droplets in the colloid can be formed from any hydrophilicmaterial suitable for forming an emulsion, containing biochemicalcomponents in a stable form; and providing an environment in which thedescribed reactions can occur.

The emulsion may be stabilized by addition of one or more surface-activeagents (surfactants). These surfactants are termed emulsifying agentsand act at the hydrophilic/hydrophobic interface to prevent (or at leastdelay) separation of the phases. Many hydrophobic liquids such as oilsand many emulsifiers can be used for the generation of biphasicemulsions; a recent compilation listed over 16,000 surfactants, many ofwhich are used as emulsifying agents (Ash, M. and Ash, I. Handbook ofindustrial surfactants. Gower Publishing Ltd: Aldershot, Hampshire, UK(1993); and Schick, Nonionic surfactants. Marcel Dekker: N.Y. (1996))such as sorbitan monooleate (SPAN™ 80; ICI)) and polyoxyethylenesorbitanmonooleate (TWEEN™ 80; ICI)).

The sequence of the oligonucleotides can be determined and verifiedusing any suitable sequencing method including, but not limited to,chemical degradation (A. M. Maxam and W. Gilbert, Methods of Enzymology,1980, 65, 499-560), matrix-assisted laser desorption ionizationtime-of-flight (MALDI-TOF) mass spectrometry (Pieles et al., NucleicAcids Res., 1993, 21, 3191-3196), mass spectrometry following alkalinephosphatase and exonuclease digestions (Wu et al., Anal. Biochem., 2001,290, 347-352), and the like.

In some embodiments, the target nucleic acids can be identified byamplifying the reacted or unreacted templated assembly reactants andsequencing the oligonucleotides from the reacted templated assemblyreactants.

Methods for enrichment of templated assembly reactants are alsodisclosed. The enrichment can select for reacted templated assemblyreactants with templated assembly targets having relevance to apathology, diseased state, an aberrant cell of interest, or a particularcellular nucleic acid target.

In some embodiments, enrichment of a pair of templated assemblyeffectors from a library of chemically-ligated oligonucleotidesspatially elicited (CLOSE) products includes obtaining a library ofoligonucleotides chemically ligated through templated assembly due tospatial proximity to cellular nucleic acid targets, amplifying thelibrary of ligated oligonucleotide-cellular nucleic acid targets, andselectively enriching for ligated oligonucleotide-cellular nucleic acidtargets, wherein the ligated targets are selected for relevance to apathology of an aberrant cell of interest or to a discontinuoushybridization to the cellular nucleic acid targets.

In some embodiments, templated assembly effectors that have hybridizedto a cellular RNA target source can be enriched towards a specifictarget RNA, where these are known from previous observations. Such atarget-directed enrichment may be applied after chemical ligation ofspatially proximal CLOSE effectors, and is herein termed“target-directed CLOSE.” The required target-directed enrichment isachievable by hybridizations between the subsets of CLOSE librarieswhich bind total cellular RNA, and a specific nucleic acid probesequence corresponding to the target of interest. Such hybridizationsare most efficient when both the CLOSE sublibrary and probes arerendered as single strands of appropriate complementarity.

As used herein, “chemically-ligated oligonucleotides spatially elicited”refers to pairs of oligonucleotides that have been chemically ligated asa consequence of their spatial proximity through hybridization to targetnucleic acid templates.

A large CLOSE collection is referred to as a CLOSE library, which can bein primary, rearranged, or amplified forms. A primary CLOSE libraryincludes chemical products of templated assembly reactions resultingfrom spatially-enabled reactions. An amplified CLOSE library can bederived directly from PCR of a primary library with a readable chemicalligation point, or indirectly, where PCR was permitted by priming sitemanipulations as achieved with a rearranged library. In someembodiments, the CLOSE products include short PCR product duplexes ofthe chemically ligated oligonucleotides. Amplification of the CLOSEproducts can be performed by amplification of the chemically ligatedoligonucleotides with primers complementary to the priming sites carriedby the specific oligonucleotides. Only oligonucleotides pairs (one fromeach separately-modified population) that have chemically joined via thetemplated assembly reaction are potentially amplifiable by PCR, byvirtue of the linkage produced between the oligonucleotides.

Excess unbound templated assembly reactants can also be removed aftertemplated assembly. The unbound templated assembly reactants can beremoved by methods commonly used in the art, such as but not limited to,sequential precipitations with polyethylene glycol 8000 (PEG), enzymaticdigestion, ultrafiltration, or gel size-exclusion chromatography.

Subtraction can also be used to enrich ligated oligonucleotide pairs ofthe CLOSE library. The ligated oligonucleotide pairs derived from atarget cell or tissue from the CLOSE library can be enriched overligated oligonucleotide pairs derived from a different cell or tissue.In some embodiments, the ligated oligonucleotide pairs derived fromaberrant target cells can be enriched over ligated oligonucleotide pairsderived from a normal cell counterpart. In some embodiments, the ligatedtargets from an aberrant cell of interest can be enriched by removingligated targets derived from normal cells of interest. Subtraction maybe effected between libraries of ligated oligonucleotide pairs derivedfrom aberrant target cells and normal cells, where biotinylated normalsequences are removed after hybridization by means of solid-phasestreptavidin binding. The remaining ligated oligonucleotide pairs aftersubtraction can be further processed for identification.

A method of valuating a pair of chemically-ligated oligonucleotidesspatially elicited (CLOSE) products for templated assembly is alsodisclosed. The pair of CLOSE products as templated assembly reactantscan be modified to interact readily with a corresponding modification onanother templated assembly reactant, but will not readily interact withnatural biomolecules. The modifications can impart a reactivity in atemplated assembly reaction, such as a selectively-reactive moietyreactivity in a templated assembly reaction. Examples of aselectively-reactive moiety can include adding a bio-orthogonal reactivemoiety. In some embodiments, a pyrene group, such as pyrene maleimide,can be added on the CLOSE products.

Similar as described above, the CLOSE products can also include 5′and/or 3′ priming sites, and/or an intermediate, such as a linker orspacer. The CLOSE products can also be further processed foridentification as described herein.

In some embodiments, a library of templated assembly reactants foridentifying the templated assembly targets are disclosed. The librarycan include templated assembly reactants. In some embodiments, thelibrary includes first and second populations of templated assemblyreactants, where the templated assembly reactants include anoligonucleotide sequence and a modification for reaction in a templatedassembly reaction.

In some embodiments, a library can include chemically-ligatedoligonucleotides spatially elicited (CLOSE) products. The library canalso include at least one pair of templated assembly targets enriched toinclude oligonucleotides chemically ligated due to their spatialproximity through hybridization to cellular nucleic acid templates. TheCLOSE library can include an amplified library of chemically ligatedproducts, and enriched oligonucleotides derived from aberrant targetcells compared to normal cells.

The kits described herein can be used for discovery of novel templatingsites in cells of interest. These can be linear sites within acontinuous segment of target RNA template, discontinuous(conformationally-enabled) sites in the same target template, or siteswithin separate templates juxtaposed via higher-order nucleic acid ornucleoprotein complexes that form within specific cells.

A templating site specific to cells of interest can be identified withthe kits and methods described herein and used as a diagnostic criterionfor identifying the presence of such cells of interest within a largebackground of other cells. For example, in a sample of blood, urine,ascites, cerebrospinal fluid, bronchial lavage, oral washings andsputum, Pap smears, tissue biopsies or organs, bile, fecal matter, orother bodily fluids or parts.

In embodiments where detection is based on fluorescence, kits caninclude templated assembly reactants that generate a fluorescent signalupon ligation of the templated assembly reactants, for example pyreneexcimers, and fluorescent detection reagents. In some embodiments, kitscan include templated assembly reactants that catalyze an enzymaticreaction upon ligation of the templated assembly reactants and detectionreagents for the enzymatic read-out, such as, but not limited to,ELISAs.

Diagnostic test evaluations of a set of corresponding templated assemblyreactants and the subject may be employed. This evaluation may serve todetermine if a particular set of templated assembly reactants can becompetent to produce an effector structure in a given subject. This maybe useful if the templated assembly reactants have not been utilizedpreviously, or if a current sample is significantly different fromprevious samples, e.g. the sample contains a lower level of targetnucleic acid than previous samples. The kits and diagnostics can alsodetect the presence or absence of target nucleic acids in a sample, orthe abundance of target nucleic acids in a sample. The kits anddiagnostics may also be useful in determining if a nucleic acid targetis accessible for templated assembly reactions, providing informationabout secondary structures of a nucleic acid target in a sample. In someembodiments, the competency of the templated assembly reactants toidentify target nucleic acids can be determined.

The kits and diagnostics can include contacting the correspondingtemplated assembly reactants with a sample or multiple samples.Identification of a convenient in vitro readout for the activityproduced by a successful templated assembly reaction is also included.Such readouts may include, but are not limited to, enzymatic activitylike sandwich enzyme-linked immunosorbent and phosphatase assays,phosphorescence, immunofluorescence, bioluminescence, and the like maybe performed.

To perform the in vitro sandwich-style diagnostic evaluation assay, thefollowing steps can be carried out. A sample or samples can be obtainedfrom a subject to assay in vitro. Optionally, a target compartmentsample (e.g., tumor biopsy) and non-target compartment negative control(e.g., a sample of healthy tissue) are obtained. Samples may be lysed ina suitable buffer to release nucleic acids, which may facilitate ease ofuse or increase the sensitivity of the assay. Templated assemblyreactants can be administered to the sample or lysate. When targetnucleic acid is present, templated assembly ligation products areformed.

Ligated products can then be bound by an immobilized capture molecule.The molecule may be immobilized on a vessel, such as a microtiter platewell, or on a substrate, such as an agarose bead or magnetic bead thatis mixed with assay medium. Sample material and non-ligated reactantscan be removed and the immobilized complex can be washed. A detectormolecule specific for an accessible part of the templated assemblyligation product can be incubated with the immobilized complex, and anappropriate detection readout can be performed. In some embodiments,specificity of the detector molecule, capture molecule, or both, mayselectively detect a structure on the templated assembly ligationproduct that is not present on any templated assembly reactant beforethe templated assembly reaction occurs, such that the templated assemblyligation products can be captured and/or detected. For example, thespecificity of the capture molecule selectively detects an effectorproduct structure that is not present in the starting templated assemblyreactants, ensuring that only templated ligation products are capturedand detected.

In some embodiments, the specificity of the detector molecule canselectively detect a structure on one templated assembly reactant, andthe specificity of the capture molecule can selectively detect astructure on a different templated assembly reactant, such that atemplated assembly ligation product would include both structures andthus be detected. Sets of templated assembly reactants contained on asingle compound may be incompatible with this embodiment.

In order that the subject matter disclosed herein may be moreefficiently understood, examples are provided below. It should beunderstood that these examples are for illustrative purposes only andare not to be construed as limiting the claimed subject matter in anymanner.

EXAMPLES Example 1: Identification of Templated Assembly TargetSequences or Structures from a Sample, Using a Library of TemplatedAssembly Reactants Producing Amplifiable Linkages BetweenOligonucleotides Bearing Pre-Appended Primer Sites (Actual Example)

Two RDO populations are synthesized. Random regions are constituted of25:25:25:25 dA:dC:dG:dT ratios during phosphoramidite-based synthesis.One synthetic population has a 5′-iodo-dT modification for subsequentchemical conversion to a 5′ azide group, and a 3′-priming site for a PCRprimer, capped with a 3′-phosphate group designed to prevent unwantedpolymerase extensions from this end. The other bears a 5′-priming sitefor a PCR primer and a 3′-5-methyl-C alkyne modification (propargylgroup). Configurations of these oligonucleotides are depicted in FIGS.1A, 1B, 1C, and 1D.

RNA from a cellular source of interest is hybridized with the randomoligonucleotide populations. One principle relies on hybridization toaccessible tracts of cellular RNAs by specific members from eachlibrary. Where two oligonucleotides from both libraries anneal to RNAsequences in sufficient spatial proximity, click-reactivity is suitable.The resulting chemical joining of such proximal strands allows theirsubsequent amplification and identification. Prior to hybridization, themodified oligonucleotides are subjected to a transient heat-denaturationstep (2 minutes/80 C), but this is not applicable to the RNA target,owing to the need to preserve native secondary structures. Whole-celllysates may also be screened in an equivalent manner, where bothprotease and RNase inhibitors are used in order to protect endogenousnative folded RNA or ribonucleoprotein structures.

RNA may be prepared by any standard procedures, including, but notlimited to, kits from commercial suppliers such as Qiagen and Norgen.

RNA may be prepared in the form of a whole cytoplasmic lysate, obtainedunder gentle conditions. Such conditions may be achieved, but are notlimited to, the example of osmotic lysis, with a hypotonic buffer of 20mM Tris pH 7.4, 10 mM NaCl, and 3 mM MgCl₂. Lysis of cells should beperformed where proteins are protected by protease-inhibitor cocktailswith 1 mM phenylmethanesulfonyl fluoride (PMSF), and also in thepresence of oxidation-insensitive ribonuclease inhibitors, such as (butnot limited to) murine RNase inhibitor (New England Biolabs).

The RNA-oligonucleotide hybridizations are performed with both randomchemically-modified populations simultaneously in a 50:50 mixture withrespect to each other by molarity, in a 10-100 fold excess over RNAquantities present, calculated by assuming an average molecular weightof the cellular RNA of 1500 bases, and with 1-10 micrograms of startingRNA. Hybridizations may be effected for periods of 2-16 hours.Hybridizations can be performed in 50 mM Tris pH 7.5, 10 mM MgCl₂, 100mM NaCl, 1 mM dithioerythritol, and 2.4 units/ml murine RNase inhibitor(New England Biolabs).

When the hybridization step(s) are finished, unbound oligonucleotidesare removed by PEG precipitation, ultrafiltration or gel size-exclusionchromatography. (Random oligonucleotides that have hybridized to thecellular RNA will co-purify with the RNA as long as the conditions favorDNA:RNA duplex persistence).

In an alternative procedure, unbound oligonucleotides are depleted bytreatment with DNase I, where hybridized RNA:DNA duplexes areinsensitive to DNase I action, and unhybridized primer sites P1 and P2are protected by duplexing with 2′-O-methyl complementary strands (FIG.1C, FIG. 1D). The DNase I treatment may be used as an alternative toother purification methods, or in conjunction with subsequent PEGprecipitation, ultrafiltration or gel size-exclusion chromatography.

Cu(I)-click catalyzed reactions are then performed in 50-100 μl volumesfor 30-60 minutes/25 C. Until this step is completed, it is best topreserve the structural integrity of the target cellular RNAs, usingstringent RNase-free conditions as much as possible, and suitable RNaseinhibitors. Cu(I)-click catalysis may be performed with commercial kits,or with individual components as known in the art. Alternatively, theCu(I) component can be delivered using specific chelators, including,but not limited to, the compounds TBTA, THPTA, BTTAA and BTTES(Besanceney-Webler et al., Angewandt Chemie International Edition, 2011,50, 8051-8056).

After completion of the Cu(I)-catalyzed click reactions, thepreparations are desalted to remove copper ions, most conveniently usingsmall disposable spin columns (Biorad or Pierce).

PCR is then performed with primers matching the priming sites carried bythe specific oligonucleotides selected from the original randompopulations. Only oligonucleotide pairs (one from eachseparately-modified population) that have chemically joined arepotentially amplifiable by this PCR process, by virtue of the“biocompatible” triazole linkage produced by the specific5′-azide/3′-alkyne oligonucleotides used (FIG. 2). Such joining can bepromoted by either contiguous sites or sites juxtaposed by target RNAfolding (FIG. 2). Products can only be formed by CLOSE oligonucleotidesthat have annealed to target template in the correct orientations (FIGS.3A, 3B, 3C).

Example 2: High-Volume Sequencing and Differential BioinformaticAnalysis of CLOSE Libraries (Prophetic Example)

Herein any pairs of oligonucleotides that have been chemically ligatedas a consequence of their spatial proximity through hybridization tocellular RNA templates are referred to for convenience by the acronymCLOSE, denoting Chemically-Ligated Oligonucleotides, Spatially Elicited.A large CLOSE collection is referred to as a CLOSE library, which can bein primary, rearranged, or amplified forms.

A primary CLOSE library contains the chemical products of click chemicalreactions resulting directly from spatially-enabled reactions. Anamplified CLOSE library is thus either derived directly from PCR of aprimary library with a readable chemical ligation point, or indirectly,where PCR has become permitted by priming site manipulations as achievedwith a rearranged library.

Any amplified CLOSE library (whether directly or indirectly) is a largecollection of short duplexes of the chemically ligated oligonucleotidesdefined by the PCR primers and priming sites used and the originallyligated spatially adjacent pair of oligonucleotides.

Amplified CLOSE libraries from aberrant cells of interest vs. theirnormal counterparts may be directly subjected to sequencing andbioinformatic analyses. More focused approaches employ differentialsubtractive hybridizations to narrow the field of candidates.

Bands corresponding to the PCR amplification products of primary CLOSElibraries are excised from gels and cloned.

In some embodiments of CLOSE cloning, excised bands are cloned by meansof 1-base 5′ dA overhangs resulting from amplification with Taq DNApolymerase. Such 5′ dA-CLOSE fragments are cloned into plasmid vectorswith single base 5′ dT overhangs. Large numbers of plasmid clones insuitable E. coli hosts are isolated as mini-scale preparations, andsubjected to conventional automated sequencing with primers up anddownstream from the CLOSE insert, placed at a sufficient distance suchthat the read-through of the CLOSE insert is complete.

Sequenced CLOSE clones were uniformly in the expected configuration,where a (+) strand 22-mer dimer (corresponding to the originalsingle-stranded oligonucleotides) (from L- to R-, FIGS. 1A, 1B, 1C, and1D) is 5′ N₁₀-CT-N₁₀. A series of arbitrarily selected CLOSE clonesequences were compared to a set of randomly generated sequences of thesame pattern (FIG. 4). The CLOSE series had significantly higher GCcontent than would be expected on a purely random basis, suggesting thatthe hybridization-based selection procedure favored the greaterstability conferred by higher GC levels.

In some embodiments of CLOSE cloning, excised bands are prepared fornext-generation sequencing according to Illumina protocols. In someembodiments of CLOSE cloning, excised bands are prepared fornext-generation sequencing according to other Next-Generation Sequencingprotocols, including, but not limited to, protocols for Pyrosequencing,ABI SOLiD sequencing, Helicos, Nanopore sequencing, and Ion Torrentsequencing.

When large numbers of CLOSE clones from aberrant cell sources have beensequenced, it is prudent to compare the accumulated sequence data withcorresponding data from normal cells as closely matched to the aberrantcell targets as possible, in terms of their differentiation state andcell expression phenotypes, genotypes, and distribution ofpolymorphisms. This analysis corresponds to an in silico subtractionmethod.

Sequence data is obtained from matched normal cells to the sequenceCLOSE clones from amplified CLOSE libraries, by correspondence with theMethod used for the CLOSE library of interest from aberrant cells.

Sets of CLOSE sequence data from aberrant cells and matched normal cellsof interest are subjected to bioinformatic analyses. The (+) strands ofeach CLOSE sequence are definable as two decamer tracts separated by aCT dinucleotide, corresponding (post-amplification) to the chemicalligation point between the 3′-(5-methyl)-dC-propargyl and 5′-dT-azidegroups borne by the original oligonucleotides.

Selection criterion for rejection of candidate CLOSE clones include:failure to find any significant match between either of the decamertracts and the expressed or genomic sequences of the cells of interest.“Significance” is here defined as at least a 70% match for either tract.

CLOSE sequence pairs from the aberrant cell source of interest will beranked by their frequency of appearance from random picking of clonedCLOSE libraries (by conventional cloning and sequencing).

Using the frequency-ranking criterion as a procedural guideline, CLOSEpairs from aberrant cell sources will be screened against CLOSE pairsfrom corresponding normal sources. Where matches with the normal cellsource are identified, the matching CLOSE pairs from aberrant cells willbe excluded from further analysis.

Other criteria for flagging aberrant CLOSE sequence pairs as being ofspecial interest are: 1) Either or both of the decamer sequencescomposing a CLOSE pair matching sequences of potential relevance to thepathology of the aberrant cell of interest, or 2) where the CLOSEpair-matches are identified as occurring discontinuously on the same RNAstrand, or on separate RNA strands.

Sequences of potential interest noted for tumor cells include, but arenot limited to, genomic or expressed genes for known oncogenes or tumorsuppressors, cell cycle regulators and mediators, transcriptonalregulators and mediators, translational regulators and mediators,telomerases, cytoskeletal components, and kinases.

Example 3: Utilizing CLOSE Libraries to Identify Sequences or StructuresSpecific to Cells of Interest Through Physical CLOSE Library Subtraction(Prophetic Example)

Subtraction may be effected between libraries of ligated oligonucleotidepairs derived from aberrant target cells and normal cells, wherebiotinylated normal sequences are removed after hybridization by meansof solid-phase streptavidin binding.

Amplified CLOSE libraries obtained according to the protocols disclosedherein are derived from aberrant cells of interest.

Normal cells as closely matched as possible to the same lineage anddifferentiation state of the aberrant cells of interest are chosen.Non-limiting examples include: melanoma cells, normal melanocytes, Blymphomas, normal B cells, T lymphomas, and normal T cells.

CLOSE libraries are obtained from the matched normal cells of interest.Such libraries should be prepared in an identical manner as for thecorresponding aberrant cells, except for the use of distinct primingsites (P3, P4) in the initial oligonucleotides (FIG. 5). Also, primersused in the final amplification step should bear 5′-biotin groups, suchthat the amplified CLOSE products themselves are biotinylated on bothstrands (FIG. 5).

When obtained from PCR reactions, both normal and aberrant CLOSElibraries are phenol-extracted and precipitated with 0.3 M sodiumacetate and 2.5 volumes of ethanol, washed with 70% ethanol, dried, andredissolved in 20 μl TE. The normal biotinylated amplified CLOSE libraryis then mixed with its counterpart non-biotinylated library fromaberrant cells, in a 10:1 ratio for normal:aberrant CLOSE products. Themixed library is denatured at 95° C. for 10 minutes, and then slowlycooled to room temperature.

The re-hybridized products are then treated with excess solid-phasestreptavidin to immobilize and remove all biotinylated strands. Innon-limiting embodiments, the solid-phase streptavidin may be magneticstreptavidin beads or streptavidin-agarose. The binding capacity of anysolid-phase streptavidin matrix used should be at least 10-fold inexcess of the total number of moles of biotinylated oligonucleotides.

The solid-phase streptavidin matrix is then separated from the unboundnon-biotinylated remainder, which is constituted by oligonucleotidesfrom the aberrant cell CLOSE library that have not hybridized withbiotinylated oligonucleotides from the corresponding normal celllibrary. In embodiments where magnetic streptavidin beads are used, amagnetic separator accomplishes the pull-down of solid-phasestreptavidin. In separation embodiments where streptavidin-agarose isused, the solid-phase streptavidin is separated by centrifugation at5000 g/10 minutes.

A sample of the soluble-phase material is then amplified using primersspecific for the CLOSE library from the aberrant cell source of interest(FIG. 5). The re-amplified enriched CLOSE library is then subjected to asecond cycle of subtraction against the original normal cell CLOSElibrary. The re-amplified enriched CLOSE library is then subjected to athird cycle of subtraction against the original normal cell CLOSElibrary. The re-amplified enriched CLOSE library is then subjected tosequence analyses

Example 4: Utilizing CLOSE Libraries to Identify Sequences or StructuresSpecific to Cells of Interest Through RNA Selection (Prophetic Example)

Alternatively, oligonucleotide pairs restricted to aberrant cells may beselected through binding of cross-hybridizing pairs (within populationsderived from aberrant cells themselves) with normal cellular RNAsources.

Amplified CLOSE libraries obtained according to the protocols herein arederived from aberrant cells of interest.

CLOSE libraries are reamplified where primer P1 bears a 5′-desthiobiotinmodification, and primer P2 is unmodified (FIG. 6). Thehemi-desthiobiotinylated amplified CLOSE library is denatured at 95°C./10 minutes, and then incubated with an excess of a solid-phasestreptavidin matrix. The solid-phase streptavidin matrix is washed threetimes with Tris-buffered saline, and then the bound desthiobiotinstrands are eluted with 5 mM free biotin (FIG. 6). The eluate isdesalted and excess free biotin removed by gel size-exclusionchromatography.

The desthiobiotinyated strand corresponds to the same sense as theprimary CLOSE library obtained from the original hybridization withaberrant RNA. Matched normal cells for the aberrant cells of interestare chosen. Whole RNA preparations are isolated from the normal cellularsource.

Free desthiobiotinylated strands are denatured (80° C./5 minutes) andallowed to hybridize to the cellular RNA preparations for the same timeperiod as used for the original CLOSE library hybridization itself withaberrant cell-derived RNA. RNA preparations are not heat-treated priorto addition of the denatured CLOSE library. RNA preparations are in a2-fold molar excess over the desthiobiotinylated strands, calculated byassuming an average molecular weight of the cellular RNA of 1500 bases.This process is depicted in FIG. 7.

The hybridized RNA-CLOSE library members are separated from unboundCLOSE library members by gel size-exclusion chromatography. Samples ofthe unbound CLOSE library are re-amplified and processed under the sameconditions as disclosed above, resulting in an amplified selectedpopulation of desthiobiotinylated strands (FIG. 7).

Free desthiobiotinylated strands are hybridized to the same normal RNAtarget, under the same conditions as disclosed above. The hybridizedRNA-CLOSE library members are separated from unbound CLOSE librarymembers by gel size-exclusion chromatography.

In some embodiments, the samples of the unbound CLOSE library arere-amplified with normal (non-biotinylated) primers, to form anamplified population of selected duplex strands. In some embodiments,the samples of the unbound CLOSE library are re-amplified and processedunder the same conditions as disclosed above, resulting in an amplifiedsecondarily selected population of desthiobiotinylated strands.Following hybridization to the same normal cell RNA targets, unbounddesthiobiotinylated strands are selected, and then re-amplified withnormal (non-biotinylated) primers, to form an amplified secondarypopulation of selected duplex strands. The amplified unbound CLOSElibraries are subjected to sequence analyses.

Example 5: Evaluation of CLOSE-Derived Sequence or Structure Candidatesby Pyrene Excimer Fluorescence: Confirmation of Molecular Proximity andQuantitation of Copy Number, and Optimization of Decamer Constituents(Prophetic Example)

CLOSE candidates identified through methods disclosed above (or anycombination thereof), or any candidate pairs of sites derivedindependently, should be confirmed for their activity and efficacy insuch a way as to permit focusing on the specific candidates with thegreatest potential for driving high-level templated assembly. Anindependent measure of molecular proximity is the elicitation of excimerfluorescence between pyrene molecules.

Following application (or any combination thereof) of the methodsdisclosed above, each decamer constituent of a CLOSE pair candidate willhave identified cellular template(s) upon which it can hybridize. Basedon the known templates identified through application of the CLOSEtechnology, it may be useful in at least a subset of cases to extendeither or both of the decamer pairs, as dictated by the complementarysequences of the templates to which they target for hybridization.Extension may assist in cyto templating through thermal duplexstabilization. Such extended and optimized candidates are alsoevaluated.

The individual decamer sequences which together constitute a CLOSE pairare separately re-synthesized and labeled with pyrene groups (FIGS. 8Aand 8B). Pyrene labeling is effected by incorporating terminal thiolgroups into synthesized DNAs (at either 5′- or 3′-ends as appropriate,as reducible disulfides in each case), and subsequently reacting the —SHgroups with pyrene maleimide.

The pyrene group can be alternatively added by a pyrene maleimide with aspacer arm between the pyrene and maleimide moieties, including, but notlimited to, pyrene-4-maleimide. The sites of pyrene additions are basedon the type of CLOSE Method originally used. For CLOSE pairs identifiedwith some of the methods above, pyrene modifications are appended at thesame 5′- and 3′-ends as used for the original azide and alkynemodifications, respectively (FIGS. 1A-1D). Since CLOSE pairs identifiedwith some of the methods above contain flanking sequences between thedecamer tracts, these kinds of pairs are evaluated with pyrene groupsappended to the exact original sequences, or the decamer tracts withoutthe original flanking sequences.

Pyrene-modified CLOSE decamers are assessed for fluorescence changesupon hybridization in vitro to complementary DNA templates (FIGS. 8A and8B). The ratio between excimer and monomer (e/m) emission spectra aremeasured with a spectrofluorometer, using control template sequenceswith varying degrees of sequence mismatch. Excitation wavelength is 335nm, monomer peak emission wavelength is 375-410 nm, excimer emissionpeak is 480 nm.

For in cyto screening, pyrene modifications are performed on analogs ofCLOSE decamers with nuclease-resistant phosphodiester backbones or sugarmoieties. These include, but are not limited to, 2′-O-methyl-nucleotidesand phosphothioate nucleotides.

Nuclease-modified and pyrene-labeled CLOSE decamers are transfected intotarget aberrant cells of interest, and also matched normal counterpartcontrol cells lacking the exact target template. Fluorescencecorresponding to excimer formation is assessed by fluorescencemicroscopy, and quantitated by spectrofluorometry.

Positive excimer signals both confirm the spatial proximity of the CLOSEoligonucleotide pairs, and also, by virtue of their relative signalstrengths, provide relative transcript levels. Signal strength as acombination of both accessibility and template copy number therebyprovides a metric for relative potential templated assembly levelsbetween different CLOSE decamers equipped with effector partialstructures.

Example 6: Evaluation of CLOSE-Derived Sequence or Structure Candidatesby QPCR Amplification: Confirmation of Molecular Proximity andQuantitation of Copy Number, and Optimization of Decamer Constituents(Prophetic Example)

CLOSE candidates or any candidate pairs of sites derived independently,can be confirmed for their efficacy, and evaluated for the relativeabundances of their target templates by click ligation and QPCR. Inaddition, the same approaches as described above can be applied towardsoptimization of each candidate pair. Where decamer pairs have beenobtained from CLOSE libraries, extensions based on known target templatesequences can also be evaluated in the same manner.

Individual specific CLOSE candidates are resynthesized with analternative set of primer sites (P1 and P2, as in FIGS. 1A-1D). In someembodiments where multiplexing is initiated, a set of up to fiveseparate candidate CLOSE decameric oligonucleotides are synthesized withdistinct primer sites for each (P1.1/P2.1; P1.1/P2.2; P1.3/P2.3;P1.4/P2.4; and P1.5/P2.5).

Each pair of individual CLOSE candidates is separately incubated with anRNA preparation or a cytoplasmic lysate containing RNA andribonucleoproteins, and excess oligonucleotides removedpost-hybridization. Each preparation is subjected to click chemicalligation with Cu(I) catalysis under conditions of protection fromRNases, and then desalted. After Cu(I) click-mediated ligations anddesalting, preparations are treated with RNase A, RNase 1_(f), and RNaseIII.

Samples of preparations are then subjected to quantitative PCR (QPCR) asdepicted in FIG. 9, and described by Kono et al., Mol. Cancer Res.,2006, 4, 779-792. QPCR probes are 15-20 bases long, and complementary toa part of primer P1 region, all of one decamer, the bridging CTdinucleotide complementary to all CLOSE clones, and up to 5 bases of thesecond decamer (S2 of FIG. 9). Specific probe lengths are determined bythe base composition of the selected decamer regions) which also conferprobe specificity), such that the T_(m) of the probe-target duplex is atleast 62 C under standard salt conditions. Each probe is equipped with a5′-fluor and a 3′-quencher, such that fluorescence may be quantitated bystandard TaqMan chemistry.

The appended 5′-fluor may be, but is not limited to, FAM™, TAMRA™, CyS™Cy3™, HEX™, JOE™ or ROX™. The appended 3′-quencher may be, but is notlimited to, BHQ1™, BHQ2™, IowaBlack®-FQ, or IowaBlack®RQ. QPCR read-outs(threshold cycle numbers) are normalized to a corresponding signals froma composite panel of housekeeping genes (Vandesompele et al. 2002), orany subset or combination thereof. Relative normalized QPCR values areobtained for each candidate primer, where values are proportional to theoriginal template copy number enabling proximity-promoted click-chemicalligation.

The initial hybridizing specific candidate CLOSE pairs are set up formultiplexing. In multiplex experiments, up to five separate pairs ofspecific CLOSE decamers are simultaneously added for hybridizing to theRNA or whole-cell lysate targets described above.

The multiplexed preparations are treated as described above. Themultiplexed sets of chemically ligated specific CLOSE pairs are used forQPCR in single determinations, where each CLOSE pair itself is definedby a separate probe corresponding to the specific decamer regions ineach case, and by use of ligated pair-specific probe-quenchercombinations. The relative levels of each individual target within amultiplexed determination is derived from the specific fluorescentmarker in each case, and related to corresponding levels of normalhousekeeping gene controls.

Example 7: Evaluation of CLOSE-Derived Candidate Sequences or Structuresby Digital PCR Amplification: Confirmation of Molecular Proximity andQuantitation of Copy Number, and Optimization of Decamer Constituents(Prophetic Example)

CLOSE candidates or any candidate pairs of sites derived independently,can be confirmed for their efficacy, and evaluated for the absoluteabundances of their target templates by click ligation and digital PCR.It is desirable to gauge target transcript expression levels owing tothe possibility of template titration, as noted above. In addition, thesame approaches as described herein can be applied towards optimizationof each candidate pair. Where decamer pairs have been obtained fromCLOSE libraries, extensions based on known target template sequences (asdescribed herein) can also be evaluated in the same manner.

Individual specific CLOSE candidates are resynthesized with analternative set of primer sites (P1 and P2, as in FIGS. 1A-1D). In someembodiments where multiplexing is initiated, a set of up to fiveseparate candidate CLOSE decameric oligonucleotides are synthesized withdistinct primer sites for each (P1.1/P2.1; P1.1/P2.2; P1.3/P2.3;P1.4/P2.4; and P1.5/P2.5).

Each preparation is subjected to click chemical ligation with Cu(I)catalysis under conditions of protection from RNases, desalted, andtreated with RNases. Samples of preparations separately derived in eachspecific case are then molecularly partitioned into distinctcompartments for digital PCR, along with Taq DNA polymerase, dNTPs,standard PCR buffer with 1.5 mM magnesium chloride, cognate primers, anda specific dual-labeled probe for fluorescent quantitation of eachtargeted paired decamer (FIG. 10).

In some embodiments, molecular partitioning of components for digitalPCR is achieved by means of microcompartments, effected throughapplication of commercially available technologies, including, but notlimited to, those marketed by Bio-Rad and RainDance Technologies asQX100 and RainDrop systems, respectively. In some embodiments, molecularpartitioning of components for digital PCR is achieved by microfluidicchambers, effected through application of commercially availabletechnologies, including, but not limited to, those marketed by Fluidigm(BioMark system).

Each preparation of partitioned targets, primers, probes, and otheramplification components is subjected to thermal amplification, suchthat specific fluorescent signal is generated where amplification oftarget occurs, where signals provide a digital measure of activecompartments, and in turn quantitation of their encompassed individualtarget molecules. Compartment processing, fluorescent measurements andsubsequent enumeration of target numbers is performed according to themanufacturers' specifications and instructions.

The initial hybridizing specific CLOSE pairs are set up formultiplexing. In multiplex experiments, up to five separate pairs ofspecific CLOSE decamers are simultaneously added for hybridizing to theRNA or whole-cell lysate targets described above. The processing of thehybridizing sample and multiplexing CLOSE oligonucleotides proceeds asdescribed above.

The combined sample containing multiplexed chemically ligated pairs ofCLOSE decamers (selected by hybridization) is split into separate assaysfor each specific target determination by digital PCR amplification andanalysis. Distinct targets are specified by unique primer combinationsand unique fluor probe labels.

Multiplexing is performed at the hybridization level, but the digitalPCR analysis is performed at a 1-plex level.

The combined sample containing multiplexed chemically ligated pairs ofCLOSE decamers (selected by hybridization) is analysed by multiplexeddigital PCR, where in addition to the components specified above, eachspecific primer pair (defined for each CLOSE target), and eachfluorescently labeled probe is also present.

Each digital compartment contains multiple primers and probes, but wherespecificity within each compartment is generated by sequencing matchingbetween primers and probes and the single CLOSE chemically ligatedtarget molecule present in each case.

The digital PCR amplification and analysis is as specified describedabove, with the additional feature of simultaneous analysis of multiplefluorescent signals, distinguishable by virtue of their separateemission wavelengths, in accordance with the manufacturers'specifications and instructions for instruments specified above.

Multiplexing is performed both at the hybridization level, and the levelof digital PCR analysis.

Example 8: DNase Treatment for Removal of Unhybridized CLOSE Oligos, andFollow-Up Cloning and Sequencing (Actual Example)

Azide and alkyne-modified CLOSE libraries were hybridized with acellular RNA target (MU89) at 32 C for 16 hours. Incubations wereperformed in 20 μl with 200 pmol of each CLOSE library (previouslyannealed with 2′-O-Me complementary oligonucleotides to their primingsite regions), with 20 μg MU89 RNA or no-template control. Allcomponents were mixed prior to the incubation without a pre-heatingstep.

Following the hybridization, each sample was treated +/− DNase I for 4hours at 28 C, followed by phenol extraction, desalting (Bio-Rad P6 Spincolumns in 10 mM Tris pH 7.4), and precipitation. After pelleting,washing, and drying, each sample was subjected to a standard THPTA-clickreaction.

Briefly, a premix of the following components was prepared withadditions in the following order: 20 μl 70 mM Tris(3hydroxypropyltriazolyl methyl) amine (THPTA) in 0.155 M NaCl, 4 μl 500mM Na-ascorbate in 0.155 M NaCl, 2 μl 100 mM CuSO₄ in 0.155 M NaCl, and2.6 μl of this premix was then added to each of the tubes for the clickreaction, such that the final volume was 50 μl in x1 phosphate-bufferedsaline. Tubes were incubated for 30 minutes/0 C (on ice), and then 2hours/25 C. At the end of the incubation period, tube contents weredesalted though Bio-Rad PC columns as above, and 0.5 μl of each ( 1/100)was subjected to PCR amplification with primers matching the CLOSEoligonucleotide priming sites. The PCR cycle used the touchdownamplification strategy, with final temperature of 60 C, and 22 cycles atthe final touchdown temperature.

Products were analyzed on a 15% acrylamide gel (FIG. 11; Lane 1, CLOSEoligonucleotides+RNA template+DNase; Lane 2, CLOSE oligonucleotides+RNAtemplate without DNase; Lane 3, CLOSE oligonucleotides with notemplate+DNase; Lane 4, CLOSE oligonucleotides with no template andwithout DNase). Results showed presence of carry-over of CLOSEoligonucleotides irrespective of the presence of template (Lanes 2 and4), but only in the presence of RNA template was a band observedpost-DNase treatment (Lane 1 vs. Lane 3). The band in Lane 1 (amplifiedCLOSE oligonucleotides+RNA template+DNase) corresponding the expectedsize for a chemically ligated CLOSE dimer was excised and re-amplifiedwith the original primers to increase the available yield.

Products were cloned with the pGEM-Teasy vector system (Promega) andindividual plasmid clones were sequenced with primers upstream anddownstream of the insertion point of the cloned fragments. Sequenceswere compared with the human transcriptome via BLAST searches. Of 31clones analyzed, a number showed matches to specific cellular RNAs for≥16/20 bases within the regions corresponding to the two decamericrandom regions of each monomeric CLOSE oligonucleotide.

Expression of candidate cellular RNAs in the original MU89 melanoma cellsource was tested by PCR with primers specific for each candidate RNAtarget. The following RNAs were expressed in MU89 and emerged as initialcandidates for further CLOSE analysis: NOL9, OTUB1 (transcript variant2), BRCA2, MAPKAPK2, and ALPK1 (transcript variants 1 and 2).

CLOSE oligos: 1) TRT-AK: (SEQ ID NO: 45)CATCTCCACCTCCATAACCCANNNNNNNNNNC^(Me) - propargyl; 2) AZC-TRT-n2:(SEQ ID NO: 46) azide-dT NNNNNNNNNNAGGTGATAGGTGGAGGTGGTA-p;Primers for amplification of the ligated CLOSE oligos: 1) Trz.F:(SEQ ID NO: 47) CATCTCCACCTCCATAAC; 2) Trz.R-n2: (SEQ ID NO: 48)TACCACCTCCACCTATCACCT; Protector oligonucleotides with 2′-O-methylbackbones: 1) TrzFco-2OM: (SEQ ID NO: 49) UGGGUUAUGGAGGUGGAGAUG;2) TrzR-n2-2OM: (SEQ ID NO: 50) UACCACCUCCACCUAUCACCU;

Example 9: Protocol for Removal of Unhybridized CLOSE Oligonucleotidesby Sequential PEG Precipitations (Actual Example)

3.2% polyethylene glycol 8000 (PEG), in the presence of 2M NaCl, wasuseful for removal of almost all unhybridized CLOSE oligonucleotides.Briefly, melanoma cell line MU89 RNA (9.0 μg; prepared by Qiagen RNAeasyprotocol) was mixed with 200 pmol of CLOSE oligonucleotides (200 pmoleach of oligonucleotides TRT-AK and AZ-TRT-n2 (see Example 8)preannealed with equimolar amounts of 2′-O-Me primer site-protectingstrands (see Example 8), or 200 pmol of the same CLOSE oligonucleotideswithout any protecting strand pre-annealing. Each preparation (50 μlfinal volume) was constituted with 50 mM Tris pH 8.3, 2.5 mM EDTA, 2 MNaCl, 40 units murine RNase inhibitor (Promega), with 3.2% PEG added (4μl) as the final constituent from a 40% PEG stock. After 30 minutes onice, tubes were centrifuged 10 minutes/maximal speed in a microfuge (≥14k rpm). The resulting supernatants were carefully removed and retained,and pellets redissolved into a fresh solution (50 μl) containing thesame buffer, salt, RNase inhibitor, and PEG concentrations. After anadditional 30 minutes on ice, tubes were centrifuged as before,supernatants removed and retained, and the final pellets re-dissolved in50 μl TE.

Samples of the final pellets and the first and second supernatants (5μl, 1/10 of each) were tested on a 2% agarose gel (FIG. 12). Resultsshowed that the vast preponderance of (unhybridized) oligonucleotideswere separated from the MU89 RNA and found in the first supernatants.

Example 10: Protocol for Removal of Unhybridized CLOSE Oligonucleotidesby Single PEG Precipitation and DNase I Treatment (Actual Example)

In another embodiment of CLOSE processing, a combination of a single PEGprecipitation and DNase I treatment were effective for removal of themajor portion of unhybridized CLOSE oligonucleotides. For this protocol,it is essential that the priming sites of the CLOSE oligonucleotides areprotected from DNase I attack by hybridization with complementary2′-O-methyl strands (as for Example 8). Hybridizations with targetcellular RNAs (performed as detailed in Example 1; most commonly at 30C) were subjected to precipitation with 3.2% PEG, using the same saltand buffer conditions as for Example 9. Following this, click reactionswere performed (always with parallel controls of samples treatedidentically but without the click reagents) followed by desalting, usingconditions as for Example 8. Then, DNase I treatments were performed at28 C in x1 RQ DNase I buffer (Promega) for 4 hours. Samples were thenphenol extracted, precipitated with 20 μg glycogen/0.3 M sodiumacetate/3 volumes ethanol, pelleted, washed with 1 ml 70% ethanol,dried, and reconstituted in 25 μl TE buffer, prior to PCR analysis (asfor Example 8). All treatments were conducted in the presence of 0.6units/ml murine ribonuclease inhibitor (New England Biolabs) until theend of the DNase I treatment. This process as whole is schematicallydepicted in FIG. 13. Results obtained were comparable to FIG. 11,whereby the combination of the PEG/DNase treatments were effective inremoving unhybridized CLOSE oligonucleotides.

Example 11: Definition and Analysis of Different Forms of DiscontinuousCLOSE Sites (Actual Example)

Application of the CLOSE process requires certain definitions ofspecific potential sites when these are discontinuous in terms ofprimary target RNA sequences. L- and R-CLOSE oligonucleotides (FIG. 1)form a 22-mer with an intervening CT sequence, either from contiguoushybridization sites, or sites which are proximally spatial butnon-contiguous in target sequence (FIG. 14). With respect to the latter,the positioning of the hybridizing L- and R-CLOSE oligonucleotides alongthe template is significant for the kinds of secondary structures whichcan result in site spatial proximities. Herein, the arrangement whereCLOSE L- and R-oligonucleotides bear effector 3′ and 5′ ends facingtowards each other (the conventional orientation for contiguous sites)is termed an “Endo” configuration; the opposite orientation (effector 3′and 5′ ends facing away from each other) is termed an “Exo”configuration (FIG. 14). In many cases Exo configurations will fail topromote reactivity, since functional effector groups are not directedtowards each other. However, positioning of target sites in the contextof certain secondary structures may favor Exo over Endo configurations.This is the case when hybridization sites exist within target templateloops of sufficient size, (FIG. 15) where Endo rather than Exoorientations are spatially separated. This was initially tested withmodel effector partials (short oligonucleotides bearing alkyne and azideclick groups) and longer oligonucleotides designed to assume loopstructures through internal regions of self-complementarity. Within theresulting loop structures formed, these oligonucleotides possessedcomplementary sites to the click oligos, arranged in either Exo(“Loop-Exo1”) or Endo (“Loop-Endo1”) configurations. Clickoligonucleotides (50 pmol each for 5′-azide and 3′-linear alkyne labeledstrands) and Loop templates (50 pmol) were initially annealed in 25 μlx1 M buffer (10 mM Tris pH 7.5, 10 mM MgCl₂, 50 mM NaCl, 1 mMdithioerythritol) by heating 2 minutes at 80 C and cooling to roomtemperature.

Ten (10) μl from each annealing (20 pmol) were then subjected to Cu(I)click catalysis with THPTA, or in equivalent buffer lacking clickcatalyst. A premix of the following components was prepared withadditions in the following order: 20 μl 70 mM Tris(3-hydroxypropyltriazolyl methyl) amine (THPTA) in 0.155 M NaCl; 4 μl500 mM Na-ascorbate in 0.155 M NaCl; and 2 μl 100 mM CuSO₄ in 0.155 MNaCl. 2.6 μl of this premix was then added to each of the tubes for theclick reaction, such that the final volume was 50 μl in x1phosphate-buffered saline.

Tubes were incubated for 30 minutes/0 C (on ice), and then 2 hours at 25C. At the end of the incubation period, tube contents were desaltedthough Bio-Rad P6 columns as above, and precipitated with 20 μg glycogen(Sigma). After centrifugation, pellets were washed with 70% ethanol,dried, and re-dissolved in 5 μl TE. Samples of each (1 μl) were run on15% urea denaturing gels and stained with SYBR-gold. Results showed theexpected click chemical ligation product arising from templating on thelinear template (FIG. 16; Lane 2, relative to the no-click control Lane1). A corresponding click band was seen with the Loop-Exo1 (FIG. 16;Lane 4), but very little with Loop-Endo1 (FIG. 16; Lane 6), supportingthe original prediction. An additional experiment showed that theExo-configuration click activity was dependent on the loop secondarystructure, by means of a control oligonucleotide where theself-complementary regions was replaced with minimally self-interactivesequence. Following annealing and click reactions carried out in thesame manner as above, gel results showed a click product band from theExo configuration with the self-complementary loop (Lane 4, FIG. 17) butno product when the self-complementarity was removed (Lane 6, FIG. 17).The Loop oligonucleotide in FIG. 17 (Loop-Exo2) differed from that usedin FIG. 16 (Loop-Exo1) in terms of the positioning of theclick-complementary sites relative to the self-complementary region:with Loop-Exo1, the click-complementary sites were 1 base from theself-complementary region; with Loop-Exo2, this was increased to 5bases. Exo-click activity was nonetheless still observed.

Oligonucleotide sequences for FIG. 16: 5′-azide oligo: (SEQ ID NO: 51)azide-TGGACCATCT (click oligo-1); 3′-alkyne oligo: (SEQ ID NO: 52)pCTTGTCCAGC^(Me) - propargyl (click oligo-2); Linear template:(SEQ ID NO: 53) GAAATAGATGGTCCA|GCTGGACAAGCAGAA;Loop-forming template with complementary sites forclick oligonucleotides 1 and 2, in Exoconfiguration (‘Loop-Exo1’; 62-mer): (SEQ ID NO: 54)GCGCGCGCGCTGCTGGACAAGTCCTTTTTTCCTTTTTTCCTAGATGGTCCA TGCGCGCGCGC;Loop-forming template with complementary sites forclick oligonucleotides 1 and 2, in Endoconfiguration (‘Loop Endo1’; 62-mer): (SEQ ID NO: 55)GCGCGCGCGCTAGATGGTCCATCCTTTTTTCCTTTTTTCCTGCTGGACAAG TGCGCGCGCGC;Oligonucleotide sequences for FIG. 17:5′-azide and 3′-alkyne oligos, and linear template: As for FIG. 16.Loop-forming template with complementary sites forclick oligonucleotides 1 and 2, in Exoconfiguration (‘Loop-Exo2’; 60-mer): (SEQ ID NO: 56)GCGCGCGCGCTCCTTGCTGGACAAGTTTTCCTTTTAGATGGTCCATTCCT GCGCGCGCGCControl oligonucleotide for Loop-Exo2, withoutself-complementary regions (‘Ctrl-Exo2’; 60-mer): (SEQ ID NO: 57)ACGGACTGCTTCCTTGCTGGACAAGTTTTCCTTTTAGATGGTCCATTCCTT CATCAAACC

Underlined sequences show the GC regions whose self-complementarityenables loop formation. Bold sequences show sites complementary to theabove click oligonucleotides 1 and 2. AGATGGTCCA: Complementary to clickoligo-1 (SEQ ID NO:58); GCTGGACAAG: Complementary to click oligo-2 (SEQID NO:59).

Example 12: In Vitro Click Reactions with Spatially Proximal butNoncontiguous Hybridization Sites Through Stem Loops (Actual Example)

Additional tests were performed where sites complementary toclick-labeled oligonucleotides (model effector partials) were renderedspatially proximal through the formation of a stem loop in the targettemplate, such that the hybridization sites were outside of the loopitself. Template sequences for in vitro click reactions were designedsuch that stem loop structures will form at room temperature, along withappropriate control sequences lacking such structures, where the clickoligonucleotides hybridize in the Endo configuration (FIG. 18).

Click oligonucleotides (50 pmol each for 5′-azide and 3′-linear alkynelabeled strands) and various templates (50 pmol) were initially annealedin 25 μl x1 M buffer (10 mM Tris pH 7.5, 10 mM MgCl₂, 50 mM NaCl, 1 mMdithioerythritol) by heating 2 minutes at 80 C and cooling to roomtemperature.

Ten (10) μl from each annealing (20 pmol) were then subjected to Cu(I)click catalysis with THPTA, or in equivalent buffer lacking clickcatalyst. Click reactions were then performed in the same manner as forExample 11. Samples of each (1 μl) were run on 15% urea denaturing gelsand stained with SYBR-gold (FIG. 19).

Chemically modified oligonucleotides were prepared by TriLink (5′-azideoligo) or University of Wisconsin Biotechnology Facility (3′-alkyneoligo).

Oligonucleotide sequences for FIG. 19: 5′-azide oligo: (SEQ ID NO: 51)azide-TGGACCATCT (click oligo-1); 3′-alkyne click oligo: (SEQ ID NO: 52)pCTTGTCCAGC^(Me )- propargyl (click oligo-2); Linear template:(SEQ ID NO: 60) GAAATAGATGGTCCA|GCTGGACAAGCAGAA; Stem-adjacent:(SEQ ID NO: 61) AGATGGTCCA GTCGGCGCGCCTCGAAAACGAGGCGCGCCGAC GCTGGACAA G;Stem-x1 sym gap: (SEQ ID NO: 62) AGATGGTCCATGTCGGCGCGCCTCGAAAACGAGGCGCGCCGACTGCTGGAC AAG; Stem-scrambled:(SEQ ID NO: 63) AGATGGTCCAGCCCCCAGGCCGCATACGACGGCTAGGGAGCGGCTGGACAA G.

Underlined sequences show the regions whose self-complementarity enablesstem loop formation. Bold sequences show sites complementary to theabove click oligonucleotides 1 and 2. AGATGGTCCA: Complementary to clickoligo-1 (SEQ ID NO:58); GCTGGACAAG: Complementary to click oligo-2 (SEQID NO:59).

Example 13: Pyrene Excimer Activity Produced by SpecificTemplate-Directed Hybridization (Actual Example)

Pyrene excimer fluorescence can be used to demonstrate molecularproximity of CLOSE oligonucleotides on a target template, and thus serveas a means for validation of candidate targets. The following protocolfor demonstration of specificity of pyrene-labeled oligonucleotides onDNA copies of Human Papillomavirus (HPV) RNA templates was used.

Pyrene oligonucleotides with 2′ O-methyl backbones: (SEQ ID NO: 64)PyeTO.1: 5′-pyrene-(C6)-UUUCUUCAGGACACAG; PyeTO.2: (SEQ ID NO: 65)UCCAGAUGUCUUUGC-(C6)-pyrene-3′;

1 nmol HPV templates (10 μl) and 1 nmol each of PyeTO.1/PyeTO.2 (2 μleach) in 100 μl of x1 “P-buffer” (used as 10 μl of x10 stock: 200 mMTris pH 7.4, 250 mM NaCl, and 50 mM MgCl₂) were mixed and made up to 100μl final. Tubes were prepared with 100 μl mixes with PyeTO.1/PyeTO.2oligonucleotides and following templates (FIG. 20): HPV-0, HPV-1, HPV-2,HPV-3, HPV-Scr (Randomly scrambled HPV template), and No Template. FIG.21 shows PyeTO.1 and Pye TO.2 annealed on wild-type and mutant HPVtemplates.

Each were heated for 2 minutes at 80 C, and allowed to cool at roomtemperature. Tubes were centrifuged briefly and the contents added toeach to 96 blackwell plates in 1:2 dilution series (50 μl each wellfinal). Readings were taken with a Tecan spectrophotometer set forfluorescent measurement and for Becton-Dickinson 96-well black-sidedplates. (Readings were set for 335 nm excitation/480 nm emission, withinstrument-optimized fluorescent settings).

Fluorescence was observed for excimer-based excitation and emissionwavelengths, and only for specific templates. (Signals absent inscrambled and no-template controls). Although all HPV templates elicitedexcimer fluorescence, best results were seen with a 2-base offsetbetween the 5′ and 3′-labeled oligonucleotides. See FIG. 21.

Example 14: Analysis of CLOSE Candidates by CLOSE Intersection Software(Actual Example

In order to facilitate the identification of CLOSE clones, software wasdeveloped (“CLOSE intersection analysis”) to work in conjunction withfree online BLAST (Basic Local Alignment Search Tool) software,available through the National Center for Biotechnology Information.This novel software was particularly needed for identifyingnon-contiguous CLOSE hits on a single template, for which BLAST alone isnot well-suited. The basic strategy involves treating each sequenced L-and R-11-mer of a CLOSE dimer separately for the purposes of BLASTsearching of the human RNA-Seq database. (This parallels the actualsituation with hybridization of each L- and R-CLOSE oligonucleotide,prior to RNA template-directed chemical ligation). It is obvious thatwhen searching with an arbitrary 11-mer sequence among humantranscriptomic sequences, a significant number of random completematches will be expected (a random 11-mer will be found on average every4.10⁶ bases), and many more will result if the stringency is reduced toless than perfect matching. (In practice, CLOSE ligations may tolerate anumber of mismatches per oligo). These first sequences are set to bringup a maximum of 20,000 hits, which encompasses in practice hits equal toor greater than 8/11 matches. These separate hit lists (as XML files)are then scanned for common RNA-Seq file entries; thus finding fileswhich intersect for their hit matches for specific L- and R-CLOSE clonesequences. Following this, the program performs a winnowing on the basisof strandedness. Only “plus/minus” hits are relevant in this context,and therefore all others are rejected. (The input CLOSE sequences are bydefault in the “plus” orientation; since complementary hybridizingsequences in target RNAs are sought, “minus” orientation hits aremandated). Ranking of hits is then performed at two levels: a matchscore for combined L- and R-searches (maximum 22 for perfect matching),and in addition a rank based on “N values”, where N=the distance betweenthe 5′ end of the CLOSE-match sequence nearest the 5′ end of the targetand the 3′ end of the CLOSE-match sequence most distal to the 5′ end ofthe target. While in principle RNA folding could bring sites intoproximity that are very remote in terms of primary sequence, it wasreasoned that low N values (closer in proximity) may be of greaterfrequency. (For fully contiguous sites, N=0). Representative software asa flow-chart is depicted in FIG. 22, and also illustrated in FIG. 23.

An example of a CLOSE software intersection file hit was examinedfurther. From an amplified CLOSE dimeric library obtained from MU89melanoma cell RNA, one candidate was a transcript from the gene PLXNA3.In this case, the CLOSE L- and R-sites were in an Exo configuration, andthe N value was only 24 bases. To investigate further, the same PLXNA3sequence (as single stranded DNA) was tested as a model template invitro, except replacing the CLOSE sites within PLXNA3 with the samemodified click oligonucleotide 10-mers as used for Examples 11 and 12.These were placed into the flanking sequences derived from PLXNA3 inboth Exo and Endo configurations. Such templates were annealed with the10-mer click oligos, and subsequently treated with and withoutclick-catalyzing reagents as for Example 1 (FIG. 24). Results showedthat click reactions occurred in either orientation. Thus, the observedCLOSE hybridizations in the Exo configuration were compatible with clickreactivity in a model template.

Oligonucleotide sequences for FIG. 24: 5′-azide oligo: (SEQ ID NO: 51)azide-TGGACCATCT (click oligo-1); 3′-alkyne click oligo: (SEQ ID NO: 52)pCTTGTCCAGC^(Me )- propargyl (click oligo-2); Linear template:(SEQ ID NO: 60) GAAATAGATGGTCCAGCTGGACAAGCAGAA; PLXA3-Exo Model:(SEQ ID NO: 66) TTCTGGCTGGACAAG TCAAGAACCCGCAGTTCGTGTTCG AGATGGTCCAGAACA; PLXA3-Endo Model: (SEQ ID NO: 67) TTCTGAGATGGTCCATCAAGAACCCGCAGTTCGTGTTCG GCTGGACAAGGA ACA.

Bold sequences show sites complementary to the above clickoligonucleotides 1 and 2. AGATGGTCCA: Complementary to click oligo-1(SEQ ID NO:58); GCTGGACAAG: Complementary to click oligo-2 (SEQ IDNO:59). Underlined sequences corresponds to the N-region for the PLXNA3CLOSE hit.

Example 15: Demonstrations of the Template Titration Effect with ModelEffector Partials (Actual Example)

The effect of excess target template on bimolecular effector partialassembly can be inferred from a priori reasoning (FIG. 25), stemmingfrom the predicted sequestration and dilution of effector partials uponexcess target templates, reducing the frequency whereby two effectorpartials pair on the same template with concomitant directed templatedassembly. This was initially tested using pyrene fluorescence (Examples5 and 13) as a read-out for spatial proximity between oligonucleotideshybridizing to sites closely linked on an oligonucleotide template.Varying amounts of the template HPV-1 (wild-type; FIG. 20) were mixedwith a constant 1 nmol of each pyrene-labeled effector oligonucleotide(PYE-TO.1, PYE-TO.2; FIG. 14), subjected to a 5 min/80 C heating andcooling to room temperature, and then read for fluorescence with a Tecanspectrophotomer (as for Example 13). Results showed a fluorescence peakat 1:1 molar ratio, followed by a linear decline as far as monitored(FIG. 26; at an 8-fold effector molar excess).

In an alternative test, templated in vitro reactivity betweenclick-labeled oligonucleotides was used. In this case, an RNAoligonucleotide served as the template, since high concentrations oftemplate would interfere with the gel-band assay read-out unlessremoved, and the RNA strands were readily removable by alkalinehydrolysis. The template oligonucleotide used in this case was an RNAversion of the same linear DNA template as previously used (Examples 11and 12). Click-labeled effectors as previously used (Examples 11 and 12)were used at 50 pmol each, and mixed with varying amounts of the RNAtemplate bearing complementary sequences, in were initially annealed in25 μl x1 M buffer (10 mM Tris pH 7.5, 10 mM MgCl₂, 50 mM NaCl, 1 mMdithioerythritol) Samples were heated 1 minutes at 70 C, cooled to roomtemperature, and treated with and without click-catalyzing reagents inthe same manner as for Example 11, followed by desalting. Then all but acontrol sample were treated in 75 μl with 0.2 M NaOH for 20 minutes/70C, neutralized with 1.2 M acetic acid (13. 5 μl) and 1 M Tris (3.8 μl)to a final volume of 100 μl. Samples were then ethanol precipitated (3volumes) with 20 μg glycogen and 0.3 M sodium acetate. Followingpelleting and washing with 70% ethanol, samples were redissolved in 5 μlTE. 1 μl of each of these preparations was denatured at 98 C for 5minutes in 98% formamide, 10 mM EDTA, and run on 15% denaturing ureagels. Gel analysis showed that in the absence of alkaline hydrolysis,the RNA template was visible and had been effective in promoting clickreactivity between the labeled oligonucleotides (FIG. 27). In thisexperiment, MU89 RNA was included as a specificity control, and notemplated effector assembly was found. A titration effect was alsoclearly demonstrable with the RNA oligonucleotide as template. Hereoptimal click product formation occurred at 10:1 template:effectorratio, but was almost absent at 100:1 template:effector ratio. Thisgeneral trend was reproducible in subsequent tests.

It was notable that while the fluorescence-based assay gave peakactivity at equimolar levels (FIG. 26), the RNA-templated assembly wasimproved at higher template levels, up to at least as much as a 10:1molar ratio (FIG. 27). It is very likely that this apparent divergencecan be ascribed to the nature of the respective templates. In thepyrene-based assay, the DNA template has little propensity for formationof secondary structures, whereas the RNA template can form a small stemloop (FIG. 27). Moroever, RNA duplexes have increased thermal stabilityover cognate DNA helices. Thus, the annealing of the DNA oligonucleotideeffectors with the RNA template competed with internal annealing of theRNA strand itself, resulting in an increased requirement for templateover equimolarity in order to give optimal results. Even so, when theRNA template levels were high enough, the titration effect is evident,severly limiting the amount of product. Overall, the theoreticaltitration effect (FIG. 25) is clearly demonstrable with realexperimental systems, but other factors in addition to effector/templateratios per se can influence the point at which template levels becomecounter-productive.

In turn, these results confirm that measuring the expression levels ofcandidate CLOSE targets is an important adjunct experimental goal(Examples 6 and 7).

Oligonucleotide sequences for FIG. 27: 5′-azide oligo: (SEQ ID NO: 51)azide-TGGACCATCT (click oligo-1); 3′-alkyne click oligo: (SEQ ID NO: 52)pCTTGTCCAGC^(Me )- propargyl (click oligo-2); Linear RNA template:(SEQ ID NO: 68) GAAAUAGAUGGUCCA|GCUGGACAAGCAGAA;

Bold sequences show sites complementary to the above clickoligonucleotides 1 and 2. AGAUGGUCCA: Complementary to click oligo-1(SEQ ID NO:69); GCUGGACAAG: Complementary to click oligo-2 (SEQ IDNO:70).

Example 16: Target-Directed CLOSE Analysis with BCR-ABL Target (ActualExample)

In contrast to the general CLOSE approach, Target-Directed CLOSE focuseson known tumor-specific transcripts. An expressed tumor-specifictranslocation is a good model for the this directed form of CLOSEtechnology, where both segments spanning the fusion junction correspondto normal transcripts. In such circumstances, a tumor-specific linearcontiguous translocation is by definition restricted to the junctionsequence itself. In contrast, folding of the transcripts (which areoften very large) has the potential to produce multiple discontinuoussites that are unique to the translocation (shown schematically in FIG.28). These sites in term may be found by CLOSE analysis, withapplication as templated assembly targets.

The BCR-ABL translocation transcript has long been known as a marker anddriver (via the expression of the fusion BCR-ABL kinase) of chronicmyelogeous leukemias, and certain other transformed states. It isstrongly expressed in the leukemic cell line K562, which was used in theexperimental work for this Example.

Whole cellular RNA from K562 cells was used to perform CLOSE analysis asfor Example 1, and following the hybridization, unhybridized CLOSEoligonucleotides were removed according to the protocol described inExample 10. Amplified CLOSE chemically-ligated dimers (templated onglobal K562 RNA) were then used prepare single-strands corresponding tothe same sense as the original CLOSE library oligonucleotides. Toaccomplish this, asymmetric PCR was performed with the top (desired)strand in a 10-fold excess over the bottom strand, which was alsobiotinylated. Following 35 cycles of amplification uder theseconditions, all products bearing the bottom strand (whether completeduplexes or single strands annealed with the bottom primer or partialextension products) were removed on streptavidin magnetic beads. Thisprocess and its utility is shown in FIG. 29.

A single-stranded probe in the same sense as the original cellulardefined RNA target is then necessary. Although the original CLOSEhybridizations are subject to RNA folding (thus enabling thejuxtaposition of sites separated in terms of primary base sequence), itis not necessary that such structures be recapitulated for theTarget-Directed CLOSE capture. While the L- and R-CLOSE sites mayhybridize to discontinuous sites, all that is required is that either L-or R-regions bind to the capture probe (FIG. 30). It is also notessential that the entire natural transcript sequence be used. In thecase of BCR-ABL, it is considered essential to span the transcriptbreakpoint region, since CLOSE clones binding to both BCR and ABL arenecessary to establish full tumor specificity, and with very long probes(within various isoforms, some >8 kb) the probability of selecting BCR-or ABL-restricted CLOSE clones increases. A DNA probe of 1338 bases(1338-probe) spanning the breakpoint was accordingly used (FIG. 31).

To render single-stranded in the correct sense, the 1338-probe wasamplified from reverse-transcribed K562 RNA, with the bottom strandbiotinylated. After binding the product to streptavidin magnetic beads,the desired top strand was obtained by denaturation with 0.1 M sodiumhydroxide/5 mM EDTA (20 seconds), followed by rapid ethanolprecipitation with 20 μg glycogen/0.3 M sodium acetate. After pelletingand washing with 70% ethanol, the single-stranded probe was dried andreconstituted in TE buffer.

Single strands for both the 1338-probe and primary K562 RNA-selectedCLOSE products were hybridized for 6 hours at 30 C, after which it isnecessary to separate the unbound CLOSE fraction. Several options existin this case. One non-limiting approach is to use agarose gels,including the PippinPrep apparatus (Sage Science). This is shownschematically in FIG. 32A. Separation in such a gel system isfacilitated by the large size differential between CLOSE dimericoligonucleotides and probe sequence. The probe and hybridized CLOSEstrands co-migrate; their mobilities may be identified by SYBR-goldstaining following by band excision and nucleic acid elution. A mockband with the same mobility as the probe from CLOSE products lacking thehybridization probe may be included as a control (FIG. 32A).

CLOSE products co-migrating with the probe are re-amplified, and used toprepare single-stranded material as above. This enables theTarget-Directed CLOSE cycle to proceed with hybridization of first-roundCLOSE selected single-stranded product with the same probe, withprogressive enrichment of specifically-hybridizing sequences achievablewith each cycle run. After at least two cycles, CLOSE products may becloned and subjected to sequence analysis as above.

Results after two such cycles showed that of 22 sequenced clones, 50%showed matches to both BCR and ABL sequences (the remainder showedmatches to either BCR or ABL, but not both). Examples of cloneswith >8/11 matches for both L- and R-sequences are also shown in FIG.32A. Note that since the probe is a subsection of the entire transcript,and L/R sites may have hybridized to discontinuous segments of thelatter, it is not necessarily the case that both will match with theprobe sequence. However, by the same token, a necessary validationrequirement is that at least one matching CLOSE sequence falls withinthe boundaries of the probe. Cited examples (FIG. 32B) of candidatesfulfilling this condition were discontinuous across the junctionsequence, and exhibit the Exo-configurations, as defined above.

Example 17: Identification of Templated Assembly Target Sequences orStructures from a Sample, Via Processing of Unnatural 5′-5′ Linkages toAllow Amplification of Chemically-Ligated Pairs (Prophetic Example)

Separate populations of oligonucleotides with 5′-azide or 5′-cycloalkynegroups are synthesized, bearing random tracts with specific flankingsequences (depicted in FIGS. 33A and 33B). Folded RNA target structuresmay promote proximity between either 5′-5′ or 3′-3′ ends (FIGS. 34A and34B), enabling click reactivity to produce unnatural strand linkages(shown for 5′-5′; FIG. 35). Flanking sequences constitute priming sitesat one end of each oligonucleotide (P1 and P2), and at the other ends,shorter regions (“adapting sites”; A1 and A2; FIG. 35) for enablingenzymatic rearrangements and dimer amplifications. Each adapting sitecontains a recognition site for a separate restriction enzyme (E1 and E2of FIG. 35), where the recognition site for each is distinct, but wherethe overhangs produced after duplex cleavage with each are mutuallycompatible for ligation. Upon ligation of DNA ends produced by E1 and E2cleavage, the resulting ligated E1-E2 product is not cleavable by eitherenzyme. Primer sites are designed to exclude the recognition sequenceschosen for E1 and E2.

Since no form of 5′-5′ chemical ligation is directly readable by anynucleic acid polymerase, the manner of chemical linkage of 5′-azide or5′-cycloalkyne groups to the above oligonucleotides is not crucial,provided the site of stable chemical bonding between the active azide oralkyne groups to the terminal 5′ nucleic acid moiety is bridged by aspacer arm or spacer group of at least 6 carbon atoms (FIGS. 36A and36B). In some embodiments, the azide group is linked to the nucleic acid5′ end through reaction with N-hydroxysuccinimde, and the alkyne groupthrough an appended hexanyl group.

Separate populations of 5′-azide and 5′-cycloalkyne-modifiedoligonucleotides of the above configurations are hybridized with wholeRNA preparations from cells of interest, or alternatively whole cellularRNA-protein preparations. Hybridizations are performed with eacholigonucleotide population in a 50:50 mixture with respect to each otherby molarity, in a 10-100 fold excess over RNA quantities present,calculated by assuming an average molecular weight of the cellular RNAof 1500 bases, and with 1-10 micrograms of starting RNA. Hybridizationsmay be effected for periods of 2-16 hours.

Following hybridization, proximity-induced spontaneous reactions between5′-azide and strained 5′ cycloalkyne moieties, excess oligonucleotideremoval, and desalting are performed. Preparations are then treated withRNase A and RNase 1. Resulting preparations include excess unchangedoligonucleotide strands, through inability to react via lack of spatialproximity, and minority desired 5′-5′ reacted products.

All resulting oligonucleotide strands are rendered double-stranded. Thiscan be effected by means of primers complementary to Priming Site 1 (P1)and Adapting Site 2 (A2), and extending each with all fourdeoxynucleotide triphosphates and Klenow fragment of DNA Polymerase I ofE. coli, such that each new strand is extended as far as the 5′-5′junctional point (FIG. 37).

When directed cleavage of the extended duplex is effected, it isundesirable for sequences in the random regions to be cleaved throughchance occurrence of restriction sites for the enzymes used forcleavage. In view of this, an alternative embodiment uses adeoxynucleotide triphosphate mixture consisting of5-methyl-deoxycytidine triphosphate, deoxyadenosine triphosphate,deoxyguanosine triphosphate, and thymidine triphosphate, such thatduplexes hemimethylated for 5-methylcytosine are generated in thecomplements to the random regions. Cleavage enzymes that are sensitiveto 5-methylcytosine hemimethylation are accordingly used. Also, sincehemimethylation should be prevented in adapting regions A1 and A2 wherecleavage occurs, a 5′-phosphorylated strand complementary to region A1is annealed with templates prior to extension reactions. (Adaptingregion A2 is kept unmethylated through priming from its non-methylatedcomplementary strand; FIG. 38). Since the complementary strand to regionA1 should not be displaced during primer extension, anon-strand-displacing polymerase is used, such as T4 DNA polymerase(FIG. 38). The resulting nick between the 5′-phosphorylated complementto region A1 and newly extended strand is sealed with T4 DNA ligase(FIG. 38).

The resulting extended duplexes are then cleaved with an enzymerecognizing restriction site E2 (FIG. 37). In some embodiments, theenzyme E2 specifically corresponds to Age I, recognizing the sequenceACCGGT to produce a four-base overhang 5′-CCGG.

In subsequent steps, the following conditions are imposed: a) Preservethe linkage information between proximally-hybridized sequences duringthe ligation-mediated rearrangement process that enables amplification;b) Maintain a microenvironment where cleaved sequences are in highconcentration relative to each other, thus driving their religation; andc) Sequester unreacted strands into individually-isolated compartments,preventing their ligation-mediated reassortment that would give spuriousamplification signals (signals which have not resulted from originalclick reactions driven by proximate templating). These conditions areachievable by means of in vitro compartmentalization.

In vitro compartmentalization is effected by making water-in-oilmicrocompartments to encompass individual molecules from the populationof unreacted oligonucleotides and 5′-5′ click ligated dimers, asrendered double-stranded, and cleaved with enzyme corresponding to siteE2. Microcompartments are formed from reagent-grade mineral oil anddetergents, with added desired internal components, under conditions ofprecisely controlled stirring as described by Davidson et al., 2009(FIG. 39). During the formation of water-in-oil microcompartments, thefollowing components are present in excess, such that each compartmentwill receive the same buffer composition (50 mM potassium acetate, 20 mMTris-acetate, pH 7.9/25 C including 1 mM ATP and 10 mM magnesium acetateions), and at least one copy of the protein T4 DNA ligase and a proteinrestriction enzyme recognizing site E1. Since the microcompartments arein large excess of the molecular species present, on average only oneligated molecule is incorporated into each compartment (FIG. 39).Likewise, unligated fragments are partitioned into microcompartments aswell (FIG. 40). In some embodiments, the E1 restriction enzyme is Xma I,recognizing the sequence CCCGGG to produce a four-base overhang 5′-CCGGcompatible with Age I. Upon ligation of overhangs from Age I and Xma Icleavage, the resulting sequence is ACCGGG, cleavable by neither enyzme.

Microcompartments are incubated for 2 hours/37 C, and then 2 hours/20 C.Within each compartment bearing an individual 5′-5′ chemically ligateddimer, cleavage with Xma I is followed by subsequent ligation witheither another Xma I overhang (the reverse of the original cleavage) orligation with the single Age I end present in the same compartment (FIG.41). Xma I-Xma I religations are recleavable by Xma I, but Age I-Xma Iligations are not, and thus inevitably become the predominant species ineach microcompartment (FIG. 42). Compartments whose oligonucleotideswere not initially chemically ligated into dimers (FIG. 39) cannotparticipate in this re-ligation/re-cutting cycle.

Microcompartments are then disrupted by treatment with diethyl ether.Specific oligonucleotide pairs from the original random populations,selected by spatial proximity on RNA templates, are amplifiable byvirtue of the rearrangement process described above.

Example 18: Identification of Templated Assembly Target Sequences orStructures from a Sample, Via Processing of Unnatural 3′-3′ Linkages toAllow Amplification of Chemically-Ligated Pairs (Prophetic Example)

Separate populations of oligonucleotides with 3′-azide or 3′-cycloalkynegroups are synthesized, bearing random tracts with specific flankingsequences (depicted in FIG. 43).

Since no form of 3′-3′ chemical ligation is directly readable by anynucleic acid polymerase, the manner of chemical linkage of 3′-azide or3′-cycloalkyne groups to the above oligonucleotides is not crucial,provided the site of stable chemical bonding between the active azide orcycloalkyne groups to the terminal 3′ nucleic acid moiety is bridged bya spacer arm or spacer group of at least 6 carbon atoms (FIGS. 44A and44B). In some embodiments, the azide group is linked to the nucleic acid3′ end through reaction with N-hydroxysuccinimde, and the cycloalkynegroup through an appended hexanyl group.

Separate populations of 3′-azide and 3′-cycloalkyne-modifiedoligonucleotides of the above configurations are hybridized with wholeRNA preparations from cells of interest, or alternatively whole cellularRNA-protein preparations. Hybridizations are performed with eacholigonucleotide population in a 50:50 mixture with respect to each otherby molarity, in a 10-100 fold excess over RNA quantities present,calculated by assuming an average molecular weight of the cellular RNAof 1500 bases, and with 1-10 micrograms of starting RNA. Hybridizationsmay be effected for periods of 2-16 hours.

Following hybridization, proximity-induced spontaneous reactions between5′-azide and strained 5′ cycloalkyne moieties, excess oligonucleotideremoval, and desalting are performed. Resulting preparations includeexcess unchanged oligonucleotide strands, through inability to react vialack of spatial proximity, and minority desired 3′-3′ reacted products.

All resulting oligonucleotide strands are rendered double stranded. Thiscan be effected by means of primers complementary to Priming Site 2 (P2)and Adapting Site 1 (A1), and extending each with all fourdeoxynucleotide triphosphates and Klenow fragment of DNA Polymerase I ofE. coli, such that each new strand is extended as far as the 3′-3′junctional point (FIG. 45).

When directed cleavage of the extended duplex is effected, it isundesirable for sequences in the random regions to be cleaved throughchance occurrence of restriction sites for the enzymes used forcleavage. In view of this, an alternative embodiment uses adeoxynucleotide triphosphate mixture consisting of5-methyl-deoxycytidine triphosphate, deoxyadenosine triphosphate,deoxyguanosine triphosphate, and thymidine triphosphate, such thatduplexes hemimethylated for 5-methylcytosine are generated in thecomplements to the random regions. In some embodiments, cleavage enzymesthat are sensitive to 5-methylcytosine hemimethylation are accordinglyused. Also, since hemimethylation should be prevented in adaptingregions A1 and A2 where cleavage occurs, a 5′-phosphorylated strandcomplementary to region A2 is annealed with templates prior to extensionreactions. (Adapting region A1 is kept unmethylated through priming fromits non-methylated complementary strand; FIG. 16). Since thecomplementary strand to region A1 should not be displaced during primerextension, a non-strand-displacing polymerase should be used, such as T4DNA polymerase (FIG. 16). The resulting nick between the5′-phosphorylated complement to region A1 and newly extended strand issealed with T4 DNA ligase (FIG. 46).

The resulting extended duplexes are then cleaved with an enzymerecognizing restriction site E2. In some embodiments, the enzyme E2specifically corresponds to Age I, recognizing the sequence ACCGGT toproduce a four-base overhang 5′-CCGG.

In subsequent steps, the following conditions are imposed: a) Preservethe linkage information between proximally-hybridized sequences duringthe ligation-mediated rearrangement process that enables amplification;b) Maintain a microenvironment where cleaved sequences are in highconcentration relative to each other, thus driving their religation; andc) Sequester unreacted strands into individually-isolated compartments,preventing their ligation-mediated reassortment that would give spuriousamplification signals (signals which have not resulted from originalclick reactions driven by proximate templating). These conditions areachievable by means of in vitro compartmentalization.

In vitro compartmentalization is effected by making water-in-oilmicrocompartments to encompass individual molecules from the populationof unreacted oligonucleotides and 3′-3′ click ligated dimers, asrendered double-stranded, and cleaved with enzyme corresponding to siteE2. Microcompartments are formed from reagent-grade mineral oil anddetergents, with added desired internal components, under conditions ofprecisely controlled stirring as described by Davidson et al. 2009 (FIG.47). During the formation of water-in-oil microcompartments, thefollowing components are present in excess, such that each compartmentwill receive the same buffer composition (50 mM potassium acetate, 20 mMTris-acetate, pH 7.9/25 C including 1 mM ATP and 10 mM magnesium acetateions), and at least one copy of the protein T4 DNA ligase and a proteinrestriction enzyme recognizing site E1. Since the microcompartments arein large excess of the molecular species present, on average only oneligated molecule is incorporated into each compartment (FIG. 47).Likewise, unligated fragments are partitioned into microcompartments aswell (FIG. 48). In this non-limiting example, the E1 restriction enzymeis Xma I, recognizing the sequence CCCGGG to produce a four-baseoverhang 5′-CCGG compatible with Age I. Upon ligation of overhangs fromAge I and Xma I cleavage, the resulting sequence is ACCGGG, cleavable byneither enyzme.

Microcompartments are incubated for 2 hours/37 C, and then 2 hours/20 C.Within each compartment bearing an individual 3′-3′ chemically ligateddimer, cleavage with Xma I is followed by subsequent ligation witheither another Xma I overhang (the reverse of the original cleavage) orligation with the single Age I end present in the same compartment (FIG.49). Xma I-Xma I religations are recleavable by Xma I, but Age I-Xma Iligations are not, and thus inevitably become the predominant species ineach microcompartment (FIG. 50). Compartments whose oligonucleotideswere not initially chemically ligated into dimers (FIG. 48) cannotparticipate in this religation/recutting cycle.

Microcompartments are then disrupted by treatment with diethyl ether.Specific oligonucleotide pairs from the original random populations,selected by spatial proximity on RNA templates, are amplifiable byvirtue of the rearrangement process described above.

Example 19: Identification of Templated Assembly Target Sequences orStructures from a Sample, Via Processing of 5′-3′ Linkages where theChemical Ligation Between Pairs of Oligonucleotides is not Compatiblewith Direct Polymerase Read-Through (Prophetic Example)

In some cases, it may be useful or even essential to screen for 5′-3′proximal linkages with click groups that cannot be directly read-throughby polymerases. At least two major factors are operative in thiscontext: 1) If pre-activated click reactants (as with strainedcyclo-octynes, for example) are used, the need for Cu(I) catalysis iscircumvented; and 2) Pre-activated click reactants can be used forscreening within living cells, which is difficult or impossible when therequirement for Cu(I) catalysis exists.

Separate populations of oligonucleotides with 5′- and 3′-click groupsare synthesized. Either (5′-cycloalkyne plus 3′-azide), or (5′-azideplus 3′-cycloalkyne) sets of populations can be used, since there is norequirement for polymerase read-through. All oligonucleotides bearrandom tracts with specific flanking sequences (depicted in FIG. 51).Flanking sequences constitute priming sites at one end of eacholigonucleotide (P1 and P2), and at the other ends, shorter regions(“adapting sites”; A1 and A2) for enabling enzymatic rearrangements anddimer amplifications. Each adapting site contains a recognition site fora separate restriction enzyme (E1 and E2 of FIG. 51), where therecognition site for each is distinct, but where the overhangs producedafter duplex cleavage with each are mutually compatible for ligation.Upon ligation of DNA ends produced by E1 and E2 cleavage, the resultingligated E1-E2 product is not cleavable by either enzyme. Primer sitesare designed to exclude the recognition sequences chosen for E1 and E2.

Since in Example 4, there is no requirement for 5′-3′ chemical ligationsto be directly readable by any nucleic acid polymerase, the manner ofchemical linkage of azide or cycloalkyne groups to the aboveoligonucleotides is not crucial, provided the site of stable chemicalbonding between the active azide or alkyne groups to the terminalnucleic acid moiety is bridged by a spacer arm or spacer group of atleast 6 carbon atoms (FIGS. 52A, 52B, 52C, and 52D). In someembodiments, the azide moiety is linked to either the nucleic acid 5′end or 3′ end through reaction with N-hydroxysuccinimde, and the alkynemoiety to either the nucleic acid 5′ end or 3′ end in the form anappended cycooctyne group.

Separate populations of azide and alkyne-modified oligonucleotides ofthe above configurations are hybridized with whole RNA preparations fromcells of interest, or alternatively whole cellular RNA-proteinpreparations. Hybridizations are performed with each oligonucleotidepopulation in a 50:50 mixture with respect to each other by molarity, ina 10-100 fold excess over RNA quantities present, calculated by assumingan average molecular weight of the cellular RNA of 1500 bases, and with1-10 micrograms of starting RNA. Hybridizations may be effected forperiods of 2-16 hours.

Click reactivity occurs directly as a consequence of acceleratedreactivity between strained alkyne groups in close proximity withazides, obviating the need for Cu(I) catalysis.

Given the circumvention of the Cu(I) catalytic requirement, labeledoligonucleotide populations may be introduced into living cells, for incyto hybridization. Hybrid oligonucleotides are synthesized withnuclease-resistant phosphodiester backbones or sugar moieties, exceptwhere there is a need for restriction enzyme cleavage in order to effectthe desired rearrangments that permit amplification (FIGS. 53A and 53B).All oligonucleotide termini (including those capped with click groups)are composed of modified segments. Where these constitute the A1 and A2regions containing restriction sites (FIG. 51), the A1 and A2 regionswith normal bases and backbones are extended by 3 bases with modifiedbackbones to deter exonucleolytic attack. Modified segments of theseoligonucleotides, include, but are not limited to,2′-O-methyl-nucleotides and phosphorothioate nucleotides.

In some embodiments, partially nuclease-resistant oligonucleotides areintroduced into target cells of interest by commercially availabletransfection reagents, including, but not limited to Lipofectamine andFugene.

Following hybridizations, the method proceeds as in Example 2 in termsof treatment with ribonucleases. In the embodiments where in cytoscreening is used, cells are disrupted and subjected to treatments withboth RNases and proteases. Protease treatments include, but are notlimited to, Proteinase K. Following treatments, preparations aredepleted of low-molecular weight products by gel size exclusionchromatography.

Resulting preparations include excess unchanged oligonucleotide strands,through inability to react via lack of spatial proximity, and desired5′-3′ reacted products. All resulting oligonucleotide strands arerendered double stranded. This can be effected by means of primerscomplementary to Adapting Site 1 (A1) and Adapting Site 2 (A2), andextending each with all four deoxynucleotide triphosphates and Klenowfragment of DNA Polymerase I of E. coli, such that each new strand isextended from, or as far as, the 5′-3′ junctional point (FIG. 54).

In embodiments where modified nucleic acids are used for in cytoscreening, the primer extension procedure is modified. Where ribosemoieties are modified as 2′-O-methyl derivatives, reverse transcriptaseenzymes may be used for extension purposes instead of Klenow fragment,using the same A1 and A2 primers as described above.

When directed cleavage of the extended duplex is effected, it isundesirable for sequences in the random regions to be cleaved throughchance occurrence of restriction sites for the enzymes used forcleavage. In view of this, a deoxynucleotide triphosphate mixtureconsisting of 5-methyl-deoxycytidine triphosphate, deoxyadenosinetriphosphate, deoxyguanosine triphosphate, and thymidine triphosphate isused, such that duplexes hemimethylated for 5-methylcytosine aregenerated in the complements to the random regions. In some embodiments,cleavage enzymes that are sensitive to 5-methylcytosine hemimethylationare accordingly used. (Adapting regions A1 and A2 are kept unmethylatedthrough priming from non-methylated complementary strands; FIG. 54).

The resulting extended duplexes are then cleaved with an enzymerecognizing restriction site E2. In this non-limiting example, theenzyme E2 specifically corresponds to Age I, recognizing the sequenceACCGGT to produce a four-base overhang 5′-CCGG.

In subsequent steps, the following conditions are imposed: a) Preservethe linkage information between proximally-hybridized sequences duringthe ligation-mediated rearrangement process that enables amplification;b) Maintain a microenvironment where cleaved sequences are in highconcentration relative to each other, thus driving their religation; andc) Sequester unreacted strands into individually-isolated compartments,preventing their ligation-mediated reassortment that would give spuriousamplification signals (signals which have not resulted from originalclick reactions driven by proximate templating). These conditions areachievable by means of in vitro compartmentalization.

In vitro compartmentalization is effected by making water-in-oilmicrocompartments to encompass individual molecules from the populationof unreacted oligonucleotides and 5′-3′ click ligated dimers, asrendered double-stranded, and cleaved with enzyme corresponding to siteE2. Microcompartments are formed from reagent-grade mineral oil anddetergents, with added desired internal components, under conditions ofprecisely controlled stirring as described by Davidson et al. 2009 (FIG.55). During the formation of water-in-oil microcompartments, thefollowing components are present in excess, such that each compartmentwill receive the same buffer composition (50 mM potassium acetate, 20 mMTris-acetate, pH 7.9/25 C including 1 mM ATP and 10 mM magnesium acetateions), and at least one copy of the protein T4 DNA ligase and a proteinrestriction enzyme recognizing site E1. Since the microcompartments arein large excess of the molecular species present, on average only oneligated molecule is incorporated into each compartment (FIG. 55).Likewise, unligated fragments are partitioned into microcompartments aswell (FIG. 56). In some embodiments, the E1 restriction enzyme is Xma I,recognizing the sequence CCCGGG to produce a four-base overhang 5′-CCGGcompatible with Age I. Upon ligation of overhangs from Age I and Xma Icleavage, the resulting sequence is ACCGGG, cleavable by neither enyzme(FIG. 57).

Microcompartments are incubated for 2 hours/37 C, and then 2 hours/20 C.Within each compartment bearing an individual 5′-3′ chemically ligateddimer, cleavage with Xma I is followed by subsequent ligation witheither another Xma I overhang (the reverse of the original cleavage) orligation with the single Age I end present in the same compartment. XmaI-Xma I religations are recleavable by Xma I, but Age I-Xma I ligationsare not, and thus inevitably become the predominant species in eachmicrocompartment (FIG. 58). Compartments with unreacted oligonucleotidesare partitioned from other potentially ligatable molecules (FIG. 56).

Microcompartments are then disrupted by treatment with diethyl ether.Specific oligonucleotide pairs from the original random populations,selected by spatial proximity on RNA templates, are amplifiable byvirtue of the rearrangement process described above.

In another embodiment of Example 19, “communication” withmicrocompartments is effected by means of nanodroplets, as described byMiller et al., Nature Methods, 2006, 3, 561-570).

Example 20: Validation of In Vitro Compartmentalization for Containmentof the CLOSE Rearrangement Process with a Model System (Actual Example)

It was desired to validate both the enzymatic rearrangement process andthe ability of in vitro compartmentalization to contain a singlemolecular rearrangement, such that the information embodied in eachCLOSE dimer is preserved. The most efficient way to approach this waswith specific click-labeled oligonucleotides, whose sequences renderthem distinguishable from each other.

Oligonucleotide sequences (A-D) for Example 20: A. 5′ Azide(SEQ ID NO: 71) CTCCATAACCCATGG ACATGTACCGGTGATCC B. 5′ Hexynyl(SEQ ID NO: 72) GATCCCCGGGCTATG TCTAGAGGAGAAGGAGA C. 5′ Azide(SEQ ID NO: 73) CTCCATAACCCAA GGATCC TCACCGGTGATCC D. 5′-Hexynyl(SEQ ID NO: 74) GATCCCCGGGTACC GAGCATAGGAGAAGGAGAwhere “Azide” indicates an azide group coupled via anN-hydroxysuccinimide intermediate, and “hexynyl” denotes an alkyneseparated from the DNA carrier by means of a 6-carbon linear spacer.Underlined sequences indicate restriction sites: A, Nco I; B, Xba I; C,Bam HI; D, Asp718I. Bold sequences correspond to regions which arerandomized in Examples 17, 18, and 19. Sequences CTCCATAACCCA (SEQ IDNO:75) and AGGAGAAGGAGA (SEQ ID NO:76): truncated forward (sense) andreverse (antisense) primer sites for amplification, respectively.

Model oligonucleotides A-D can be distinguished from each by restrictionsite digestion (as duplexes) or by PCR amplification with extendedprimers specific for each oligonucleotide.

In the first stage of the model, all four possible azide-alkynecombinations of oligonucleotides A-D were mixed in high concentrations(10 pmol/μl; 50 μl volumes) and subjected to untemplatedcatalyst-assisted click reactions as for Example 1, with the samepost-reaction desalting. When reactions were tested on denaturingacrylamide gels, a biphasic click-specific band pattern was reproduciblyobserved: a “top” band at higher apparent molecular (roughly twice themonomeric molecular weight), and a “bottom” band with slightly slowermobility than the original bands (FIG. 59). Both top and bottom bandswere purified by excision from preparative gels, with multiple lanes toavoid lane saturation (FIG. 59) were crushed and oligonucleotidesallowed to diffuse out, followed by their precipitation andreconstitution.

At this point it was deemed necessary to test whether either or bothbands could undergo the enzymatic rearrangement process which permitsamplification (Examples 17, 18, and 19). Although performing thisprocess in free solution does not preserve the information from eachclicked molecule, the enzymatic requirements are constant, and successin this case also validates the rearrangement process itself. Samples ofboth Top and Bottom bands were initially rendered double-stranded withKlenow DNA Polymerase I fragment, dNTPs, and suitable primers:

Primers for rendering model or actual 5′-5′library oligonucleotides double-stranded: E1-Ext: (SEQ ID NO: 77)GGATCACCGGT Trz.R: (SEQ ID NO: 78) GCCTCTAAGTCTCCTTCTCCT

The double-stranded preparations were then treated with or without Xma Iand Age I, and in turn with or without T4 DNA ligase. Following this,samples were amplified with the primers Trz.F (CATCTCCACCTCCATAACCCA)(SEQ ID NO:79) and Trz.R (as above), and run on non-denaturing acylamidegels. Bands of the expected size (68 bp) were observed from both Top andBottom preparations, but only after both restriction enzyme digestionand religation, fully in support of the planned rearrangement process(FIG. 60). It was concluded that both Top and Bottom bands arerearrangeable 5′-5′ adducts, where the faster-migrating Bottom band ismost likely a self-folded denaturation-resistant form. For thecontinuation of the model process, the Top bands were used. Although inlower evident yields than the Bottom bands, the Top bands were much moreeasily resolved from unreacted monomers.

Accordingly, samples of the four possible 5′-5′ adducts (FIG. 59) wereshown to be essentially pure on denaturing gels (FIG. 61). Samples ofthese (1 pmol) were extended with Klenow enzyme as above, and thentested with Xma I/Age I and religation with T4 DNA ligase. In additionto each adduct separately, two mixes of adducts with heterologousconstituent oligonucleotides were also included in the rearrangementtests. These were adducts B_(H)+F_(H) (corresponding to 5′-5′ joins oforiginal oligonucleotides A/B and C/D respectively) amd adductsD_(H)+H_(H) (corresponding to 5′-5′ joins of original oligonucleotidesA/D and C/B respectively). After the enzymatic treatments, all adductpreparations showed amplificable material (with the same process andprimers as for FIG. 60), but nothing was observable without enzymes(FIG. 62).

At this point, it was possible to use the model oligonucleotidedetection system for evaluating the success of IVC in enablingmolecule-specific rearrangements without loss of CLOSE information fromunnatural chemical ligations. The principle of this system is depictedschematically in FIG. 63. Where specific 5′-5′ adducts are held inisolation, either in homogeneous solution or through successfulmicrocompartmentalization, only one possible rearrangment product ispossible. However, if different adducts of the same configuration aremixed (or if the IVC is inadequate), cross-overs between differentadducts will occur during the ligation step, which will destroy theinformation contained in specific 5′-5′ CLOSE oligonucleotides. If PCRprimers specific for each original oligonucleotide sequence (A-D) can bedesigned, then the amplification patterns with various primercombinations will directly report the state of adduct rearrangements.

Primers with the desired specificity were designed for the originalclick-labeled oligonucleotides A-D. Here specific primer pairs wereintended to amplify only a particular direct (single-molecule)rearrangement, or a particular cross-over product. For example, for theBH adduct, after rearrangement, the desired primers would amplify onlyB-A sequence, and likewise for the BH adduct, correct primers shouldspecifically amplify only D-C sequence. When the BH and FH adducts aremixed, two possible cross-over products can be formed: B-C, and D-A, forwhich specific primer combinations are also desirable. Note that withinsuch mixtures, the “direct” products will be able to form as well as thecross-over products.

Preparations of the B_(H) and F_(H) adducts were used after they hadbeen rendered double-stranded, and subjected to the Age I/Xma I/DNAligase treatment for rearrangment. These were performed as singleadducts and as mixtures (B_(H)+F_(H) adducts) at high sensitivity. Itwas found (FIG. 64) that the primer pairs designed to be specific fordirect rearrangements of the B_(H) and F_(H) adducts were satisfactory(products seen only from homologous rearrangements, or from theB_(H)+F_(H) mixtures). Of the two possible cross-over primer pairs, one(for B-C cross-over) showed low but detectable cross-specificity(showing product with (B_(H) alone), but the other cross-over primerpair (D-A) appeared to be highly specific (FIG. 64). This primer pairwas according used further, since either pair is sufficient todemonstrate the presence of absence of cross-overs.

Oligonucleotides sequences for rearrangement and cross-over testing:These were extensions of the ‘general primers Trz.F and Trz.R (asabove), which will amplify any combination of A-D rearrangements.

Primers specific for direct B_(H )rearrangement: Trz.F + Te:(SEQ ID NO: 80) CACCTCCATAACCCATGGACA Trz.R + Ce: (SEQ ID NO: 81)CTAAGTCTCCTTCTCCTCTAGACAPrimers specific for direct F_(H )rearrangement: (SEQ ID NO: 82)Trz.F + Ae: CCACCTCCATAACCCAAGGAT (SEQ ID NO: 83)Trz.R + Ae: TCTAAGTCTCCTTCTCCTATGCTPrimers specific for B_(H )- F_(H )cross-over rearrangement #1 (B-C):Trz.F + Te/Trz.R + Ae (as above).Primers specific for B_(H )- F_(H )cross-over rearrangement #2 (D-A):Trz.F + Ae/Trz.R + Ce (as above).

Bold sequences correspond to the extensions beyond the 3′ ends of Trz.Fand Trz.R.

It was also desired to perform an additional control, where samples ofseparately rearranged B_(H) and F_(H) adducts were separately mixed justprior to PCR (This is distinct from reactions where the B_(H) and F_(H)adducts were mixed prior to the rearrangement process itself, wherecross-overs are promoted, as shown in FIG. 64). This second control settests whether cross-overs can occur in this system through artefactualPCR effects. It was found (FIG. 65) that no such PCR-induced cross-overeffects occurred.

With the primer specificity confirmed, the use of the modeloligonucleotides for testing in vitro compartmentalization couldproceed. Here, duplexed 5′-5′ adducts precut with Age I (Example 17,FIG. 39) and Xma I/T4 DNA ligase/buffer/1 mM ATP were mixed with thenecessary oil and surfactants for emulsion formation. (Precutting withAge I simplifies the enzymatic requirements for inclusion in theemulsion mixes). It was initially shown that both Xma I and T4 DNAligase were active in 1×CutSmart buffer (New England Biolabs) in thepresence of 1 mM ATP, which was thus used during in mixes for emulsionformation. If emulsions and compartmentalization are successful, nocross-over product should be detectable after rearrangements are allowedto proceed within the emulsions themselves, when both precut B_(H) andF_(H) adducts are present initially.

Emulsion mixes were prepared by the method of Davidson et al., CurrentProtocols in Molecular Biology, 2009, 24.6.1-24.6.12 with the exceptionthat Triton-X100 was omitted. Emulsions themselves were generated in thefollowing manner, always using positive-displacement pipettes (Gilson)for dispensing the viscous fluids: the emulsion mix corresponded to 950μl mineral oil (molecular biology grade, Sigma), 45 μl Span-80 (Sigma)and 5 μl Tween-80 (Sigma). 50 μl mixes of Age I-precut adducts (inpredefined quantities) or controls were prepared in x1 CutSmart bufferwith 1 mM ATP, containing Xma I and T4 DNA ligase. (Enzymes were onlyadded immediately prior to emulsion formation, and all preparations werekept chilled at 0 C on ice.) The emulsion mix was placed in a 13 ml tube(17×95 mm; VWR Scientific) and chilled prior to addition of a 9.5×9.5 mmspinbar (Fisher Scientific) and mixed in the 13 ml tube contained withan ice-bearing flask, and centrifuged with a Corning PC-410D stirrer at1150 rpm for 2 minutes. Following this, the chilled adduct/buffer/enzymemix (50 μl) was added slowly (10×5 μl aliquots) to the top of thespinning emulsion, after which the centrifuging was continued foranother 10 minutes. In some tests, this was followed by an additionalsonication step to homogenize microdroplet size. Five rounds ofthree-second mid-strength sonication bursts were used, with chilling oftubes between bursts. Then the emulsions were carefully transferred to 2ml tubes, and incubated for 1 hour at 30 C; 4 hours at 25 C. Controlreactions were prepared in 50 μl volumes, as above, but were notsubjected to the emulsification process. At the end of the incubationperiods, the emulsions were broken with diethyl ether. Initially 500 μlTris-buffered saline was added to each tube (including non-emulsifiedcontrols, which were then maintained on ice), and then the followingextraction procedure was used: 1×0.5 ml ether; 2×1.0 ml ether; 1×0.5 mlether, with centrifugations of 2 minutes/13,000 rpm each time toseparate phases. Materials in all aqueous phases (includingnon-emulsified controls) were then precipitated with 40 μg glycogen/0.3M sodium acetate/3 volumes ethanol, washed with 70% ethanol, dried, andreconstituted in 10 μl TE.

Tests were performed with inputs of 5.10⁹ molecules each of B_(H) andF_(H) adducts (precut with Age I) as “high concentration”, and 10⁸molecules each as “low concentration”, each under enzymatic rearrangmentconditions with and without emulsion-mediated compartmentalization.

To enhance the sensitivity of detection, a nested primer strategy wasused for analysis of products post-emulsification. A set of first roundprimers each 5′ to the above rearrangement-specific primers were used:

Trz.F + T: (SEQ ID NO: 84) CATCTCCACCTCCATAACCCAT(upstream of Trz.F + Te, sequence as above)  Trz.R + C: (SEQ ID NO: 85)GCCTCTAAGTCTCCTTCTCCTC (upstream of Trz.R + Ce, sequence as above)Trz.F + A: (SEQ ID NO: 86) CATCTCCACCTCCATAACCCAA(upstream of Trz.F + Ae, sequence as above) Trz.R + A: (SEQ ID NO: 87)GCCTCTAAGTCTCCTTCTCCTA (upstream of Trz.R + Ae, sequence as above)

Results of such an experiment are shown in FIG. 66. As expected, evenwith the low-concentration adducts, in the absence ofcompartmentalization, both B_(H) and F_(H) rearrangement products wereobserved, along with cross-over bands (Lanes L-Ct, FIG. 66).High-concentration adducts subjected to both spinning and sonication foremulsification also showed clear-cut cross-over bands (Lanes H-Sc, FIG.66). However, low-concentration adduct mixes, whether subjected tospin-only or spin plus sonication for emulsification, showed only directB_(H) and F_(H) rearrangement product bands, with no evidence forcross-over.

It was concluded that:

1) the model system was a valid test for containment of therearrangement process within in vitro microcompartments;

2) high amounts of adduct mixes can saturate the IVC process, allowinguncompartmented material to persist, and cross-over to occur; and

3) suitable amounts (10⁸ molecules or less) of adduct mixes can becontained by the IVC and molecule-specific rearrangements can bedetected.

Example 21: Amplification of CLOSE 5′-3′ Linked Clones byCircularization and Inverse PCR (Prophetic Example)

In the case of non-amplifiable 5′-3′ CLOSE joins (but not 5′-5′ or3′-3′), an alternative strategy exists in addition tomicrocompartmentalization. Here the 5′- and 3′-ends of joined CLOSEsingle strands are defined sequences, whereby complementaryoligonucleotides to each can anneal and, thus, provide 5′-overhangs forself-ligation purposes. (CLOSE clones with the terminal definedsequences are sufficiently long for self-circularization to occur). Uponenzymatic circularization, primers P1 and P2 (FIG. 67) enable inverseamplification, including the information carried within the randomizedregions (a specific sequence for each CLOSE clone).

The circularization must be performed at low concentration, to minimizethe likelihood of inter-molecular ligations, as opposed to the desiredintra-molecular circularization.

Various modifications of the described subject matter, in addition tothose described herein, will be apparent to those skilled in the artfrom the foregoing description. Such modifications are also intended tofall within the scope of the appended claims. Each reference (including,but not limited to, journal articles, U.S. and non-U.S. patents, patentapplication publications, international patent application publications,gene bank accession numbers, and the like) cited in the presentapplication is incorporated herein by reference in its entirety.

1. A method for identifying templated assembly targets comprising:synthesizing a first population of templated assembly reactants and asecond population of corresponding templated assembly reactants, whereinthe first and second populations of templated assembly reactantscomprise oligonucleotide sequences; hybridizing both populations oftemplated assembly reactants to target nucleic acids; performing atemplated assembly reaction, wherein the hybridized first population oftemplated assembly reactants and the hybridized second population ofcorresponding templated assembly reactants undergo templated assembly;and identifying the target nucleic acids that hybridized to either thefirst or second population of templated assembly reactants thatunderwent templated assembly, wherein the hybridized target nucleicacids are the templated assembly targets. 2-14. (canceled)
 15. A libraryof templated assembly reactants for identifying templated assemblytargets comprising at least a first and second population of templatedassembly reactants, wherein the templated assembly reactants comprise anoligonucleotide sequence and a modification for reaction in a templatedassembly reaction.
 16. The library of claim 15, wherein the templatedassembly reactants further comprise either a 5′ or a 3′priming siteadjacent to the oligonucleotide sequence.
 17. The library of claim 15,wherein the modification in the first population of templated assemblyreactants further comprises a 5′-azide and the modification in thesecond population of templated assembly reactants further comprises a3′-alkyne group.
 18. The library of claim 15, wherein the modificationin the first population of templated assembly reactants further comprisea 5′-alkyne and the modification on the second population of templatedassembly reactants further comprise a 3′-azide group.
 19. The library ofclaim 15, wherein the templated assembly reaction is selected from thegroup consisting of a click chemical reaction, a Staudinger reduction, anon-traceless Staudinger ligation, and a native chemical ligation. 20.The library of claim 19, wherein the modification is specific for atraceless Staudinger ligation selected from either a tracelessphosphinophenol Staudinger ligation or a traceless phosphinomethanethiolStaudinger ligation. 21-22. (canceled)
 23. The library of claim 15,wherein the oligonucleotide sequence further comprisesnuclease-resistant phosphodiester backbones or nuclease-resistant sugarmoieties.
 24. A kit for identifying templated assembly targetscomprising a library of oligonucleotides for identifying templatedassembly targets comprising oligonucleotide sequences modified ascorresponding templated assembly reactants and reagents.
 25. The kit ofclaim 24, wherein the oligonucleotide sequences further comprise 5′, 3′,or 5′ and 3′ priming site.
 26. The kit of claim 24, wherein theoligonucleotide sequences further comprise a 5′ or a 3′ modification fortemplated assembly.
 27. The kit of claim 24, wherein the oligonucleotidesequences comprises random sequences of about 5 to about 100 nucleotideslong.
 28. The kit of claim 24, wherein the oligonucleotide sequencescomprises gene specific sequences of about 5 to about 100 nucleotideslong.
 29. A method for enrichment of a pair of templated assemblytargets from a library of chemically-ligated oligonucleotides spatiallyelicited (CLOSE) products comprising: obtaining a library ofoligonucleotides chemically ligated through templated assembly due tospatial proximity to cellular nucleic acid targets; amplifying thelibrary of ligated oligonucleotide-cellular nucleic acid targets; andselectively enriching for ligated oligonucleotide-cellular nucleic acidtargets, wherein the ligated targets are selected for relevance to apathology of an aberrant cell of interest or to a discontinuoushybridization to the cellular nucleic acid targets.
 30. (canceled)
 31. Apair of templated assembly targets enriched from a library ofchemically-ligated oligonucleotides spatially elicited (CLOSE) productscomprising oligonucleotides chemically ligated due to their spatialproximity through hybridization to cellular nucleic acid templates. 32.The templated assembly target of claim 31, wherein the CLOSE librarycomprises short PCR product duplexes of the chemically ligatedoligonucleotides.
 33. The templated assembly target of claim 31, whereinthe CLOSE library comprises an amplified library of chemically ligatedproducts.
 34. The templated assembly target of claim 31, wherein theCLOSE library comprises an amplified library of rearranged chemicallyligated products.
 35. The templated assembly target of claim 31, whereinthe cellular nucleic acid templates comprise genomic or expressed genesfor known oncogenes or tumor suppressors, cell cycle regulators andmediators, transcriptonal regulators and mediators, translationalregulators and mediators, telomerases, cytoskeletal components, andkinases. 36-37. (canceled)
 38. A method of evaluating a pair ofchemically-ligated oligonucleotides spatially elicited (CLOSE) productsfor templated assembly comprising: modifying the pair of CLOSE productsas templated assembly reactants; transfecting the pair of modified CLOSEproducts into a target aberrant cell of interest; and screening fortemplated assembly of the pair of modified CLOSE products. 39-41.(canceled)